CN115494313B - Method for determining multi-component co-adsorption interface/surface charge distribution of emulsification-foaming system - Google Patents
Method for determining multi-component co-adsorption interface/surface charge distribution of emulsification-foaming system Download PDFInfo
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Abstract
The invention relates to a method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system, which comprises the following steps: constructing an effective electric field model considering the morphological characteristics of emulsified liquid drops/foaming foam; taking a micro-element body with the area of any point dA on the interface/surface film, and establishing the relationship between the interface/surface charge distribution and the virtual intrinsic point charge under the multi-component co-adsorption effect; acquiring attribute parameters of an oil-gas-water emulsification-foaming system space; establishing a vector form of electrostatic force between interface/surface charges in an oil-gas-water emulsification-foaming system; the distribution of the interfacial/surface charges considering the tangential mechanical balance of emulsion droplets/foaming foam is determined, and the method is used for deeply revealing and separating the multi-component aggravated oil-gas-water emulsification and foaming behaviors in different production nodes of oil-gas field ground gathering and transportation treatment. The invention realizes reliable application in the representation of oil-gas-water emulsification and foaming behavior of a real working condition gathering and delivering system and the development of corresponding demulsification and defoaming technologies.
Description
Technical field:
the invention relates to an oil-water emulsification system and a gas-liquid foaming system demulsification and defoaming process technology in an oil-gas field ground process, in particular to a method for determining multi-component co-adsorption interface/surface charge distribution of an emulsification-foaming system.
The background technology is as follows:
the chemical flooding technology is mainly used for increasing the recoverable reserves in China and is divided into polymer flooding based on expanding sweep volume, surfactant flooding based on reducing interfacial tension to form wet reversal, alkali flooding based on hard film dissolution of organic acid in a neutralized rock stratum and binary/ternary composite flooding used by combination of multiple chemical agents (alkali, surfactant and polymer), wherein the ternary composite flooding comprises multiple chemical agent components such as polymer, surfactant and alkali, and in the oil field development and recovery process, the polymer molecules are used for stretching oil-water interface films or oil drops to increase the viscosity of a displacement medium, strengthen the oil washing capability of the displacement medium, expand the sweep efficiency of the displacement medium, and aggregate tiny oil drops by using the surfactant to form an oil zone, so that the oil efficiency of the displacement medium is further improved, and meanwhile, aiming at the recovery of an acid rock stratum oil-gas field, the alkali content in the ternary composite flooding is controlled to trap the oil drops or the oil drops in a dispersed state, so as to generate synergistic yield increase with the surfactant, and the residual oil film is reduced, and the saturated residual oil is produced stably.
As an oil-water emulsifying system and a gas-liquid foaming system which are generated along with the development of the full life cycle of an oil field, the oil-water emulsifying system and the gas-liquid foaming system are commonly existing in various production units along the pipeline, the pump unit and the pipeline of the oil-gas field collecting and conveying system, and due to the acidity environment, the concentration of anions and cations and the existence of a shearing flow field in the oil-gas-water emulsifying-foaming system, polymers in binary/ternary compound flooding undergo corresponding degradation reaction to generate macromolecular chains with charges at one end, and ions dissolved by alkali and surfactant are co-adsorbed on an interfacial film of emulsified liquid drops and a surface film of foaming foam. However, it is also known that these co-adsorption effects affect the ground metering and efficient operation of the treatment process of the oil-gas-water emulsification-foaming system, especially enhance the stability of the emulsified liquid droplets and the foaming foam, and the intrinsic mechanism is that when a plurality of degraded ionic components are co-adsorbed on the interfaces of the emulsified liquid droplets and the surface of the foaming foam, the thickness of the interface/surface film is increased, the stress characteristics of the interface/surface film are changed to improve the mechanical strength, and meanwhile, the free charges formed by the components adsorbed on the emulsified liquid droplets/the foaming foam excite the distribution characteristics of the interface/surface charges, so that the mechanical factors for destroying the stability of the oil-gas-water emulsification-foaming system are weakened by electrostatic force, and the interface/surface film is destroyed to realize the oil-gas-water extraction separation barrier. Therefore, revealing the boundary/surface charge distribution characteristics caused by multi-component co-adsorption in oil-gas-water emulsification-foaming systems has become the major point for explaining the difficulty of scientific problems and solving engineering problems. However, the existing knowledge is based on phenomena or experimental parameters related to emulsification and foaming stability and reflects the boundary/surface charge distribution rule laterally, and although the rule widens a new thought for the demulsification and defoaming process of an oil-gas-water emulsification-foaming system under the co-adsorption effect, the boundary/surface charge distribution determination can not be carried out by considering different co-adsorption environments and different emulsion droplet/foaming foam morphological characteristics, and the boundary/surface charge distribution determination cannot be related to the hydraulic characteristics of an external shearing flow field, so that the development of an efficient separation technology, the research and development of efficient separation equipment and the mutual coordination and cooperation of the loss of an oil-gas gathering and conveying system under a 'double carbon' target, the operation load and the overall operation efficiency are directly influenced. The method is particularly important to scientifically establish the determination method of the multi-component co-adsorption interface/surface charge distribution of the oil-gas-water emulsification-foaming system, and breaks through the defects of unification and idealization of the co-adsorption environment and description of liquid film deformation in the traditional knowledge, particularly the limitations and the problems of undefined critical electrostatic force and shearing force action.
The invention comprises the following steps:
the invention aims to provide a method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsification-foaming system, which is used for solving the problems that the mechanical response of multi-component co-adsorption interface/surface film in the emulsification-foaming system is described, particularly the relation between the multi-component co-adsorption interface/surface charge distribution and the morphological characteristics of emulsified liquid drops/foaming foam is inconvenient to operate due to the randomness of the co-adsorption environment and is limited to qualitative analysis at present and quantitative determination is not realized due to the coexistence of oil-water emulsification and gas-liquid foaming behaviors when an oil-water mixed medium is gathered and transported.
The technical scheme adopted for solving the technical problems is as follows: this method of determining the emulsification-foaming system multicomponent adsorption interface/surface charge distribution:
step one, constructing an effective electric field model considering the morphological characteristics of emulsified liquid drops/foaming foam; assuming that the interface/surface film is stretched to be in an ellipsoid shape under the action of a shearing flow field, establishing a three-dimensional coordinate system, setting an imaginary intrinsic point charge at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam, introducing a spherical electric field, intercepting a curve on the ellipsoid surface through an XOY plane, and introducing an effective electric field of any micro-element vertical normal direction of the spherical electric field on the curve:
Wherein E is the electric field intensity of the measuring point; epsilon rd The relative dielectric constant of the emulsified liquid droplets/frothed foam; a is the half axis length of the emulsified liquid drop/foaming foam in the X axis direction; b is the half axis length of the emulsion droplet/foam in the Y axis direction; c is the half axis length of the emulsion droplet/foam in the Z axis direction; z 0 Is the height of the intercepting plane; beta is an included angle formed by the direction of the electric field diverged from the center of the ellipsoid and the normal line of any point on the boundary/surface film; k=9.0×10 9 N·m 2 /C 2 The method comprises the steps of carrying out a first treatment on the surface of the q is the charge amount of the virtual intrinsic point charge;
establishing the relationship between boundary/surface charge distribution and virtual intrinsic point charge under the multicomponent co-adsorption effect: taking the infinitesimal body with the area dA of any point on the interface/surface film, wherein the capacitance of any infinitesimal body of the whole interface/surface film is equal everywhere, and the interface/surface charge distribution is related to the imaginary intrinsic point charge:
wherein δ is the interfacial/surface film thickness; c (C) bi Is the measured capacitance of the interfacial/surface film formed corresponding to the fraction of the constituent molecules; s is the interfacial/surface film area through which the current passes;
step three, obtaining attribute parameters of an oil-gas-water emulsification-foaming system space; according to the space position of the emulsified liquid drop/foaming foam, setting the origin of a three-dimensional space rectangular coordinate system at the geometric center of the emulsified liquid drop/foaming foam, constructing a simplified hexahedral space boundary of an oil-gas-water emulsification-foaming system, defining the space of the oil-gas-water emulsification-foaming system as an effective space and an ineffective space, and further dividing the effective space into a face space, a line space and a point space, thereby obtaining attribute parameters of the space of the oil-gas-water emulsification-foaming system;
Establishing a vector form of electrostatic force between interface/surface charges in an oil-gas-water emulsification-foaming system;
determining the distribution of interfacial charges/surface charges considering the tangential mechanical balance of emulsion droplets/foaming foam, and using the distribution in deep reveal of multi-component aggravated oil-gas-water emulsification and foaming behavior in different production nodes of oil-gas field ground gathering and transportation treatment to realize the efficient demulsification and separation treatment of the oil-gas-water emulsification and foaming system of tertiary oil recovery composite flooding in the oil field;
epsilon in the above rc A relative dielectric constant of the continuous phase surrounding the emulsified liquid droplets/frothed foam; phi is the volume ratio of the disperse phase of the oil-gas-water emulsification-foaming system; epsilon rc A relative dielectric constant of the continuous phase surrounding the emulsified liquid droplets/frothed foam; ρ d The density of the disperse phase in the oil-gas-water emulsification-foaming system; ρ c Is the density of the continuous phase in the oil-gas-water emulsification-foaming system; d is equivalent particle diameter before deformation of emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system; v is the interfacial/surface tension;
the specific method of the step one in the scheme comprises the following steps:
an imaginary intrinsic point charge is introduced into the emulsion liquid drop/foaming foam, so that the polarization charge generated by the polarization of the interface/surface film is equivalent to the free charge formed by the co-adsorption of the multicomponent components, and the equilibrium effect of mechanical response is consistent;
Assuming that the boundary/surface film is stretched to be in an ellipsoid shape under the action of a shearing flow field, a three-dimensional coordinate system is established, an imaginary intrinsic point charge is arranged at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam so as to enter a spherical electric field, for any point on the boundary/surface film, the included angle formed by the direction of the electric field diverged by the ellipsoid center and the normal line of the point is beta, and the spherical electric field strength of the imaginary intrinsic point charge at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam is:
wherein E is the electric field intensity of the measuring point, V/m; k is an electrostatic force constant, k=9.0×10 9 N·m 2 /C 2 The method comprises the steps of carrying out a first treatment on the surface of the q is the charge amount of the virtual intrinsic point charge, C; r is the distance between the field source point charge and the measuring point, and m; epsilon rd The relative dielectric constant of the emulsified liquid droplets/frothed foam;
then the curve equation on the ellipsoid taken through the XOY plane is:
wherein a is the half-axis length of the emulsified liquid drop/foaming foam in the X-axis direction, and m; b is the half axis length of the emulsion droplet/foam in the Y axis direction, m; c is the half axis length of the emulsion droplet/foam in the Z axis direction, m; z 0 The height of the intercepting plane is m;
converting ellipsoidal curved surface equation into hidden function form includes:
then any point (x, y, z) on the curve taken in the XOY plane 0 ) The normal vector body form of (c) is expressed as:
According to the coordinate expression form of the vector included angle, the normal vector is obtained
And straight line vector->
The cosine value cos beta of the formed projection angle is as follows:
the effective electric field of the vertical normal direction of any microelement body of the introduced spherical electric field on the curve:
the specific method of the second step in the scheme comprises the following steps:
taking a micro-element body with the area of any point dA on the interface/surface film, combining the geometric characteristics of extremely small thickness of the interface/surface film, and considering the micro-element body as a plane polar plate, and meanwhile, assuming that the components of the interface/surface film are uniform, namely the self capacitance of any micro-element body of a complete interface/surface film is equal everywhere, according to the capacitance determination, the micro-element body has:
wherein ε r The relative dielectric constant of the medium between the capacitor plates; s is the facing area of the capacitor plate, m 2 ，d s Distance m is the distance between the capacitor plates; k is coulomb constant, N.m 2 /C 2 ；
The microbody capacitance for different co-adsorption environments is expressed as:
wherein C is i The capacitance value F of the lower boundary/surface membrane microelements relative to the molecular stacking fraction of a certain component; c (C) bi Is the measured capacitance, F, of the interfacial/surface film formed corresponding to the fraction of the constituent molecules; s is the area of the interfacial/surface film through which the current passes, m 2 The method comprises the steps of carrying out a first treatment on the surface of the dA is the area of the primordial volume;
under the action of effective electric field of virtual internal point charges in emulsified liquid drop/foaming foam, the polarized charges generated by molecular polarization should be equivalent to the interface/surface charges, and are determined by capacitance values of interface/surface films, and according to the definition of parallel plate capacitance, the polarized charges are as follows:
Where u=e ⊥ Delta, Q is the charge quantity carried on the parallel plate electrode plate, C; u is the plate pressure difference, V; delta is the interface/surface film thickness, m;
then, in combination with the defined relationship between the total charge amount and the charge distribution density, the capacitance of the simultaneous micro-element is expressed as:
wherein sigma is the charge distribution density of the micro-element body, C/m 2 ；
Meanwhile, substituting the effective electric field constructed in the first step to obtain a correlation formula of boundary/surface charge distribution and virtual intrinsic point charge:
the specific method of the third step in the scheme is as follows:
the distribution probability of emulsified liquid drops/foaming foam existing in the oil-gas-water emulsification-foaming system at any position in the system space is random, and the origin of a three-dimensional rectangular coordinate system is arranged at the geometric center of the emulsified liquid drops/foaming foam according to the space position of the emulsified liquid drops/foaming foam, so that the simplified hexahedral space boundary of the oil-gas-water emulsification-foaming system is constructed as follows:
wherein a is 1 +a 2 ＝l a ，l a The length of the oil-gas-water emulsification-foaming system along the X-axis boundary is m;a 1 、a 2 the absolute values of coordinates of vertexes at two ends of the boundary at the positive half axis and the negative half axis of the X axis are respectively m; b 1 +b 2 ＝l b ，l b The length of the oil-gas-water emulsification-foaming system along the Y axis is m; b 1 、b 2 The absolute values of coordinates of vertexes at two ends of the boundary on a positive half shaft and a negative half shaft of the Y-axis are respectively m; c 1 +c 2 ＝l c ，l c The length of the oil-gas-water emulsification-foaming system along the Z axis is m; c 1 、c 2 The absolute values of coordinates of vertexes at two ends of the boundary on a positive half shaft and a negative half shaft of the Z shaft are respectively m;
assuming that the emulsification and foaming degree is uniform in the whole oil-gas-water emulsification-foaming system, if the physicochemical properties of emulsified liquid drops/foaming foams contained in any point in the system space are the same, the virtual intrinsic point charges generating boundary/surface charge distribution are consistent, and according to the principle that electrostatic force applied to a symmetrical center by a symmetrical space point is reversely counteracted, the emulsified liquid drops/foaming foams are taken as the symmetrical center, and the resultant force of electrostatic force generated by the emulsified liquid drops/foaming foams at the central position of all boundary/surface charges in a hexahedron formed by taking the boundary intersection point closest to the boundary of the oil-gas-water emulsification-foaming system as the corner point is zero;
the space of the oil-gas-water emulsification-foaming system is defined as effective space and ineffective space to distinguish the contribution degree of interface/surface film at any point to the mechanical action of the description object, so as to obtain a 1 ≥a 2 ,b 1 ≤b 2 ,c 1 ≥c 2 For example, six boundaries of dead space are expressed as:
the effective space is further divided into a face space, a line space and a point space according to the contact mode of the ineffective space and the effective space, wherein x is the same as that of the effective space 1 ＝a 2 The planes are contacted, and the boundary of the surface space taking the planes as contact interfaces is as follows:
the specific expression of the geometric center and volume of the space is:
V A ＝4(a 1 -a 2 )c 2 b 1
wherein A is the same as x 1 ＝a 2 Geometrical center coordinates of the contacted surface space; v (V) A For this spatial volume of face space, m 3 ；
Similarly, obtain and respectively match y 1 ＝-b 1 、z 1 ＝c 2 The geometric center and volume expression of the planar-contacted surface space are as follows:
V B ＝4a 2 (b 2 -b 1 )c 2
V C ＝4a 2 b 1 (c 1 -c 2 )
the same method is used for respectively acquiring and connecting
The line space geometric center and volume expression of the space straight line contact are as follows:
V D ＝2(a 1 -a 2 )(b 2 -b 1 )c 2
V E ＝2(a 1 -a 2 )b 1 (c 1 -c 2 )
V F ＝2a 2 (b 2 -b 1 )(c 1 -c 2 )
acquisition and spatial point (a) 2 ,-b 1 ,c 2 ) The geometric center and volume of the contacted point space are expressed as follows:
V G ＝(a 1 -a 2 )(b 2 -b 1 )(c 1 -c 2 )。
the specific method of the fourth step in the scheme is as follows:
the interface/surface charge existing in the effective space in the oil-gas-water emulsification-foaming system generates an external electric field by taking the interface/surface charge as a center, the vector superposition acts on emulsified liquid drops/foaming foam, and the formed electrostatic force is defined as follows:
in which Q 1 The charge quantity is the forced charge, C; q (Q) 2 The amount of charge, C, being the forced charge; r is the action distance between two charges, m; epsilon rc A relative dielectric constant of the continuous phase surrounding the emulsified liquid droplets/frothed foam;
the form size and distribution density of emulsified liquid drop/foaming foam in the oil-gas-water emulsification-foaming system are random, and the charge-volume coefficient is defined 
Reflecting the different types of total space charge amounts are:
wherein the dead space centered on the emulsified liquid droplets/frothing foam is taken as the reference space, i.e. V 0 ＝8a 2 b 1 c 2 V is the space volume of any effective space in the oil-gas-water emulsification-foaming system, m 3 The method comprises the steps of carrying out a first treatment on the surface of the Q is the total charge of any effective space, C; v (V) 0 Is the space volume, m of a reference space in an oil-gas-water emulsification-foaming system 3 ；Q 0 A reference charge amount corresponding to the reference space, C;
meanwhile, based on the average particle size of an oil-gas-water emulsification-foaming system, the volume ratio of a reference space to a total space is combined to construct the space distribution density of emulsified liquid drops/foaming foam, and then the reference charge Q is calculated 0 Associated with the imaginary intrinsic point charge q is:
wherein phi is the volume ratio of the disperse phase of the oil-gas-water emulsification-foaming system;
the charge-to-volume coefficient and the reference charge are introduced into the definition of electrostatic force:
from which the electrostatic force coefficient ζ is extracted with respect to the effective spatial attribute parameter:
substituting the electrostatic force coefficient definition according to the expression of the geometrical center coordinates and the volume of the surface space in the third step to obtain:
because the electrostatic force is that all effective spaces carry out vector superposition on electrostatic force components of emulsified liquid drops/foaming foam, the electrostatic force directions generated by different types of effective spaces are different, and the X, Y, Z axial direction of a three-dimensional rectangular coordinate system is selected as a base vector, the direction vector pointing to the origin from the geometric center in the face space is expressed as:
To eliminate the influence of the modulo of the direction vector on the electrostatic force magnitude, the conversion of the direction vector into a unit vector has:
considering that the direction unit vector has base vectors in 3 directions, the electrostatic force coefficient ζ is expanded along the directions of the 3 base vectors, and the electrostatic force coefficient vectors in different plane spaces are constructed by combining the unit vectors:
wherein:
is a base vector in the X-axis direction; />
Is a base vector in the Y-axis direction; />
Is a base vector in the Z-axis direction;
combining the expression of algebraic forms of electrostatic force, carrying out vector superposition on the electrostatic force of all the surface spaces, and converting the electrostatic force vector forms into:
similarly, the electrostatic force vector form of the line space can be obtained respectively
And electrostatic force vector form of the dot space +.>
The specific method of the fifth step in the scheme is as follows:
the interface/surface film micro-element body with the area dA is regarded as a hexahedron, and the gravity and buoyancy received by the interface/surface film micro-element body are expressed as follows:
G＝ρ d gδdA
F f ＝ρ c gδdA
wherein ρ is d For density of disperse phase in oil-gas-water emulsification-foaming system, kg/m 3 ；ρ c For density of continuous phase in oil-gas-water emulsification-foaming system, kg/m 3 ；
When the oil-gas-water emulsification-foaming system is in a shear flow field, the interface/surface film of the emulsified liquid drops/foaming foam can be subjected to the action of a shear force, so that the emulsified liquid drops/foaming foam can be affine deformed into stable ellipsoids, and the deformation characteristics of the emulsified liquid drops/foaming foam formed into ellipsoids with different radius distributions under the shearing action of different flow fields are as follows:
In the method, in the process of the invention,
d is the deformation degree of the emulsified liquid drop/foaming foam under the shearing action of a flow field; alpha is the steering angle and rad synchronously induced when the emulsified liquid drops/foaming foam deform under the shearing action of a flow field; f is a mechanism that reveals competition between viscous shear stress stretching emulsified droplets/frothed foam and interfacial/surface tension maintaining emulsified droplet/frothed foam shapeCoefficients; lambda is the viscosity ratio of the dispersed phase to the continuous phase; a and b are respectively the long axis length and the short axis length of the deformed ellipsoidal oil-water emulsion liquid drop/foaming foam, and m; mu (mu) d Is the viscosity of the disperse phase, pa.s; mu (mu) c Viscosity of continuous phase, pa.s; τ is flow field shear stress, pa; d is the equivalent particle diameter of emulsified liquid drops/foaming foam before deformation in an oil-gas-water emulsification-foaming system, and m; v is the interfacial tension, N/m;
assuming that the oil-gas-water emulsification-foaming system is an incompressible fluid, according to the principle of mass conservation, the volumes of the sphere and the ellipsoid before and after deformation are equal, and the spherical emulsified liquid drops/foaming foam particle size before deformation is obtained by a volume formula of the sphere and the ellipsoid:
considering the geometrical characteristics of affine deformation, the deformation difference of the emulsified liquid drop/foaming foam on the normal plane of the flow direction of the shearing flow field is very small, and b=c, the geometrical equation of the simultaneous ellipsoids is adopted, and the shearing stress and tangential direction vectors are extracted from the deformation characteristics:
In the method, in the process of the invention,
τ is the shear stress applied by the external shear flow field to the interface/surface film, pa; />
For this purpose, a unit vector of the direction of action of the shear stress;
the dynamic stability of the maximum deformation of the middle section of the emulsified liquid drop/foaming foam ellipsoid is taken as a balance condition, the surface charge of the interface/surface film microelements is substituted into the vector form of the interfacial space electrostatic force in the fourth step, and the tangential projection of the interfacial space electrostatic force on the interface/surface film is obtained by combining the steering angle:
and according to the definition of the electrostatic force coefficient in the fourth step, extracting geometric parameters related to effective space from the electrostatic force tangential projection to obtain the electrostatic force tangential coefficient of the face space, wherein the electrostatic force tangential coefficient is as follows:
similarly, the electrostatic force tangential coefficients ζ of the line space and the point space are respectively obtained 2τ 、ζ 3τ Further, the gravity and the buoyancy are decomposed along the tangential direction of the boundary/surface film, the shearing force corresponding to the deformation characteristic is combined, meanwhile, the boundary/surface charge distribution correlation of the second step is carried into the electrostatic force, and a tangential mechanics equilibrium equation is constructed, wherein the tangential mechanics equilibrium equation is constructed by the following steps:
in zeta 1τ 、ζ 2τ 、ζ 3τ Electrostatic force tangential coefficients of the face space, the line space, and the point space, respectively;
eliminating the area term dA of the infinitesimal in the balance equation, and meeting the imaginary intrinsic point charge value of tangential mechanical balance of the emulsified liquid drop/foaming foam is as follows:
Further, the virtual intrinsic point charge is substituted again into the correlation of the boundary/surface charge distribution in the second step, so as to obtain a specific quantitative expression of the boundary/surface charge distribution:
the invention has the following beneficial effects:
the invention firstly constructs virtual intrinsic point charges in the emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system, takes the mechanical response balance as an equivalent condition, replaces free charges formed by interfacial/surface co-adsorption with interfacial/surface polarization charges generated by polarization, considers an ellipsoid geometric equation after the emulsified liquid drops/foaming foam are subjected to shearing deformation, establishes effective electric field expression acting on an interfacial/surface film, is matched with the geometrical form of the emulsified liquid drops/foaming foam in the actual oil-gas-water emulsification-foaming system, is beneficial to extracting various electrical characteristic parameters of the interfacial/surface film from the effective electric field, and provides a scientific means for realizing electrostatic force description between the interfacial/surface charges in the oil-gas-water emulsification-foaming system; realizing the efficient demulsification and separation treatment of the oil-water emulsification-foaming system of the tertiary oil recovery compound flooding oil field.
Secondly, the invention fully considers the co-adsorption environment of different multicomponent components and different component molecular stacking fractions in the oil-gas-water emulsification-foaming system, describes the capacity of forming polarized charges by electric field excitation in different co-adsorption environments by using the capacitance parameters of the interface/surface film, combines the expression of effective electric fields, constructs the association of interface/surface charge distribution and imaginary intrinsic point charges, forms an important basis for the interface/surface charge distribution determination of the emulsified liquid drops/foaming foam, and enables the interface/surface charge distribution disclosure induced by the multicomponent co-adsorption to be possible from traditional qualitative description to quantitative determination in the oil-gas-water emulsification-foaming system.
The method for acquiring the space attribute parameters of the oil-gas-water emulsification-foaming system focuses on the correspondence of the charge distribution of the emulsified liquid drops/foaming foam and the co-adsorption effect of multiple components, the space position distribution of the emulsified liquid drops/foaming foam and the randomness of deformation sizes, and simultaneously considers the effect of electrostatic force generated between boundary/surface charges and the mechanical balance offset relationship caused by symmetrical geometric structures in the oil-gas-water emulsification-foaming system, so that the defect of critical mechanical effect parameters in the determination of the boundary/surface charge distribution of the emulsified liquid drops/foaming foam is avoided, the reliability of the construction of a boundary/surface film mechanical model in the oil-gas-water emulsification-foaming system is further ensured, and the method is beneficial to the reliable application in the characterization of oil-gas-water emulsification and foaming behaviors and the corresponding demulsification and defoaming technology development of a real working condition gathering system.
The invention is based on the essence of forming the boundary/surface charge distribution based on the multi-component co-adsorption, the space attribute division of an oil-gas-water emulsification-foaming system is taken as a basis, potential electrical factors of the deformation size of emulsified liquid drops/foaming foam are excavated, the definition of the volume-charge coefficient is introduced, thereby eliminating the errors caused by the space distribution, the co-adsorption and the deformation randomness of the micro-emulsified liquid drops/foaming foam, further relating any space charge quantity with imaginary intrinsic point charges through the expression of the average density of the emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system, laying the foundation for the univariate solution of the boundary/surface film mechanical model of the subsequent emulsified liquid drops/foaming foam, constructing the boundary/surface electrostatic force action vector form of the emulsified liquid drops/foaming foam according to the attribute parameters of the effective space, and providing a beneficial method and reference for more scientifically and deeply revealing the boundary/surface mechanical balance mechanism under the multi-component co-adsorption.
The invention breaks through the inconvenience brought by the coadsorption behavior of the multi-component in the random arrangement and aggregation of the interface/surface film in the oil-gas-water emulsification-foaming system to determine the interface/surface charge distribution, considers the deformation and the stability caused by the mechanical action of the emulsified liquid drop/foaming foam, the interface/surface film meets the law of mechanical balance, builds the interface/surface film mechanical model after the emulsified liquid drop/foaming foam deformation is stable, takes the shearing stress in the model as the association quantity, describes the correspondence between the emulsified liquid drop/foaming foam deformation and the shearing stress by combining with the Cox theory, realizes the quantitative determination of the interface/surface charge distribution in the oil-gas-water emulsification-foaming system, simultaneously effectively improves the application range of the interface/surface film mechanical model of the emulsified liquid drop/foaming in the coadsorption environment of different multi-component according to the electrostatic force vector expression form including the electrical characteristic parameters of the interface/surface film, and enables the coadsorption mechanism expression between the multi-component and the interface/surface film to develop from qualitative description to quantitative calculation, thereby providing effective deep scientific basis for the separation and the aggravation of the interface and foaming behavior of the emulsified liquid in different production nodes of oil-gas field surface gathering and transportation.
According to the invention, polarization charges generated by the virtual intrinsic point charges of the emulsified liquid drops/foaming foam are used for equivalently replacing free charges, the association between the boundary/surface charge distribution and the virtual intrinsic point charges is constructed, a boundary/surface film mechanical model of the emulsified liquid drops/foaming foam is established through the equivalent relationship of mechanical response balance, and the virtual intrinsic point charge quantity is solved through a single variable equation of tangential mechanical balance of the boundary/surface micro-elements, so that the boundary/surface charge distribution of the emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system is determined.
The invention solves the technical problem of describing the mechanical response of the multi-component co-adsorption interface/surface film in the oil-gas-water emulsification-foaming system, especially the determination of the interface/surface charge distribution under the multi-component co-adsorption effect due to the coexistence of emulsification and foaming actions during the oil-gas-water mixed medium gathering and transportation.
(eight) the invention fully considers that in a certain specific oil-gas-water emulsification-foaming system, different multi-element chemical components generate co-adsorption action to cause the difference of the interface/surface distribution of emulsified liquid drops/foams, so that virtual intrinsic point charges are used for establishing an effective electric field on an interface/surface film, and polarization charges are used for replacing free charges formed by the co-adsorption action, thereby breaking through the single suitability of the traditional qualitative interface/surface film measurement method for the geometry of the emulsified liquid drops/foams in a certain co-adsorption environment; the space attribute partitioning method of the oil-gas-water emulsification-foaming system is utilized to construct an electrostatic force vector form between boundary/surface charges, and the shear stress is described by combining with Cox theory to establish a mechanical balance equation so as to obtain the specific expression of virtual intrinsic point charges, so that the boundary/surface charge distribution of different oil-gas-water emulsification-foaming systems is quantitatively represented, a means can be provided for enriching and expanding the research of the stability mechanism of the oil-gas-water emulsification-foaming system, and the intelligent design and construction of oil field ground engineering under a 'double-carbon' target are promoted.
Description of the drawings:
FIG. 1 is a schematic diagram of the method of the present invention;
fig. 2 is an enlarged view of part B of fig. 1 in the method of the present invention.
1 oil-gas-water emulsification-foaming system 2 emulsion liquid drop/foaming foam 3 multicomponent 4 boundary/surface film 5 virtual internal point charge 6 polarization charge 7 middle section 8 effective electric field 9 effective space 10 ineffective space 11 surface space 12 line space 13 point space 14 shear flow field 15 microcell 16 boundary/surface tension 17 additional pressure 18 buoyancy 19 gravity 20 shear force 21 electrostatic force 22 steering angle.
The specific embodiment is as follows:
the invention is further described with reference to the accompanying drawings:
the method for determining the multi-component co-adsorption interface/surface charge distribution of the emulsification-foaming system is used for the efficient demulsification and defoaming technology of the ground of the oil and gas field, and comprises the following steps of:
firstly, constructing an effective electric field model considering morphological characteristics of emulsified liquid drops/foaming foam;
as shown in fig. 1, in the oil-gas-water emulsification-foaming system 1 composed of several multicomponent components 3 and emulsified liquid droplets/foaming foam 2, most of the multicomponent components 3 are aggregated and co-adsorbed on the interface/surface film 4 of the emulsified liquid droplets/foaming foam 2 due to various forces between molecules, and at the same time, free electrons are formed to be movable by degradation of the multicomponent components 3 to constitute the interface/surface charge distribution of the emulsified liquid droplets/foaming foam 2. View a in fig. 1 is a simplified structure of a middle section 7 of an emulsified liquid drop/frothing foam 2, and virtual intrinsic point charges 5 are introduced into the emulsified liquid drop/frothing foam 2, so that polarized charges 6 bound on the inner side and the outer side of a boundary/surface film 4 are excited, the polarized charges 6 are equivalently replaced with original boundary/surface charges based on equivalent conditions of mechanical response balance, and an effective electric field 8 for exciting distribution of the polarized charges 6 is formed by combining the electric field intensity of the virtual intrinsic point charges 5 with the normal component of the boundary/surface film 4.
For the emulsified liquid drop/foaming foam 2 in the oil-gas-water emulsification-foaming system 1, the free charge is ions or electrons which can move freely on the interface/surface film 4, and is influenced by the co-adsorption behavior of the multicomponent component 3 such as the surfactant, the inorganic salt in water, the polymer, the polar component of crude oil and the like added in the ternary composite flooding, in the co-adsorption environment of different chemical components 3 and different component molecule stacking fractions, the charge distribution of the interface/surface film 4 is changed to different degrees, and the polarized charge 6 is the charge generated by polarizing neutral molecules through an external electric field, is influenced by the nature of the external electric field source only, is irrelevant to the co-adsorption environment of the oil-gas-water emulsification-foaming system 1, so that an imaginary intrinsic point charge 5 is introduced into the emulsified liquid drop/foaming foam 2, and the polarized charge 6 generated by polarizing the interface/surface film 4 is equivalent to the free charge formed by the co-adsorption of the multicomponent component 3, and the dynamic response balance effect is consistent.
Assuming that the boundary/surface film 4 is stretched into an ellipsoidal shape under the action of the shearing force 20 in the external shearing flow field 14, a three-dimensional coordinate system is established, an imaginary intrinsic point charge 5 is placed in the center of the ellipsoidal emulsified liquid drop/frothing foam 2 to introduce a spherical electric field, at this time, any point on the boundary/surface film 4 is expressed, an included angle formed by the direction of the electric field diverged from the ellipsoidal center and the normal line of the point is beta, and the spherical electric field strength of the imaginary intrinsic point charge 5 at the center of the ellipsoidal emulsified liquid drop/frothing foam 2 is:
Wherein E is the electric field intensity of the measuring point, V/m; k is an electrostatic force constant, k=9.0×10 9 N·m 2 /C 2 The method comprises the steps of carrying out a first treatment on the surface of the q is the charge amount of the virtual intrinsic point charge, C; r is the distance between the field source point charge and the measuring point, and m; epsilon rd The relative dielectric constant of the emulsified liquid droplets/frothed foam.
Then the curve equation on the ellipsoid taken through the XOY plane is:
wherein a is the half-axis length of the emulsified liquid drop/foaming foam in the X-axis direction, and m; b is the half axis length of the emulsion droplet/foam in the Y axis direction, m; c is the half axis length of the emulsion droplet/foam in the Z axis direction, m; z 0 To intercept the height of the plane, m.
Converting ellipsoidal curved surface equation into hidden function form includes:
then any point (x, y, z) on the curve taken in the XOY plane 0 ) The normal vector specification of (a) can be expressed as:
according to the coordinate expression form of the vector included angle, the normal vector is obtained
And straight line vector->
The cosine value cos beta of the formed projection angle is as follows:
the curve equation is brought into simplification, and the effective electric field 8 of the spherical electric field generated by the virtual intrinsic point charge 5 in the vertical normal direction of any microcell 15 on the curve is obtained:
thus, the construction of an effective electric field model taking the morphological characteristics of emulsified liquid drops/foaming foam into consideration is completed.
(II) establishing the relationship between boundary/surface charge distribution and virtual intrinsic point charge under multicomponent co-adsorption:
Considering the difference of the co-adsorption performance of the interface/surface film 4 to the multicomponent 3 in the oil-gas-water emulsification-foaming system 1, under the co-adsorption environment of different multicomponent 3 and different component molecular stacking fractions, the distribution of the 3 types and the quantity of the multicomponent 3 types of the co-adsorbed interface/surface film 4 of the emulsified liquid drop/foaming foam 2 are different. Therefore, in the interfacial/surface charge distribution caused by the co-adsorption action, in order to reflect the influence of the co-adsorption environment of different multicomponent 3 and different component molecular packing fractions, the micro-element 15 with the area dA at any point on the interfacial/surface film 4 is taken for analysis, and the geometric characteristics of extremely small thickness of the interfacial/surface film 4 are combined, which can be approximately regarded as a planar polar plate, and meanwhile, the components of the emulsified liquid drop/foaming foam 2 are assumed to be uniform, namely, the electrical characteristic parameters of any micro-element 15 of one complete interfacial/surface film 4 are equal everywhere, according to the capacitance determination formula:
wherein ε r The relative dielectric constant of the medium between the capacitor plates; s is the facing area of the capacitor plate, m 2 ；d s Distance m is the distance between the capacitor plates; k is coulomb constant, N.m 2 /C 2 。
The capacitance of the microelements 15 in a co-adsorption environment for the different multicomponent 3 can be expressed as:
wherein C is i The capacitance value F of the lower boundary/surface membrane microelements relative to the molecular stacking fraction of a certain component; c (C) bi Is the measured capacitance, F, of the interfacial/surface film formed corresponding to the fraction of the constituent molecules; s is the area of the interfacial/surface film through which the current passes, m 2 The method comprises the steps of carrying out a first treatment on the surface of the dA is the area of the primordial volume;
under the action of the effective electric field 8 of the point charges 5 in the emulsion droplet/frothing foam 2, the distribution of the polarization charges 6 generated by molecular polarization should be equivalent to the distribution of the interface/surface charges and determined by the capacitance value of the interface/surface film 4, and the capacitance definition of the parallel plates is as follows:
where u=e ⊥ δ， Q The charge quantity of the parallel plate polar plate is C; u is the plate pressure difference, V; delta is the interface/surface film thickness, m.
The capacitance of the simultaneous micro-element 15 is expressed in terms of the defined relationship between the total charge amount and the charge distribution density:
wherein sigma is the charge distribution density of the micro-element body, C/m 2 。
Meanwhile, substituting the effective electric field 8 formed by the virtual intrinsic point charge 5 in the step (one) to obtain a correlation between the boundary/surface charge distribution and the virtual intrinsic point charge 5:
this completes the correlation of the multicomponent co-adsorption lower boundary/surface charge distribution with the hypothetical intrinsic point charge.
Thirdly, acquiring attribute parameters of the oil-gas-water emulsification-foaming system space;
the distribution probability of the emulsified liquid drops/foaming foam 2 existing in the oil-gas-water emulsification-foaming system 1 at any position in the system space is random, and the origin of the three-dimensional space rectangular coordinate system is arranged at the geometric center of the emulsified liquid drops/foaming foam 2 according to the space position of the emulsified liquid drops/foaming foam 2, so that the simplified hexahedral space boundary of the oil-gas-water emulsification-foaming system 1 is constructed as follows:
Wherein a is 1 +a 2 ＝l a ，l a The length of the oil-gas-water emulsification-foaming system along the X-axis boundary is m; a, a 1 、a 2 The absolute values of coordinates of vertexes at two ends of the boundary at the positive half axis and the negative half axis of the X axis are respectively m; b 1 +b 2 ＝l b ，l b The length of the oil-gas-water emulsification-foaming system along the Y axis is m; b 1 、b 2 The absolute values of coordinates of vertexes at two ends of the boundary on a positive half shaft and a negative half shaft of the Y-axis are respectively m; c 1 +c 2 ＝l c ，l c The length of the oil-gas-water emulsification-foaming system along the Z axis is m; c 1 、c 2 And the absolute values of coordinates of vertexes at two ends of the boundary on a positive half axis and a negative half axis of the Z axis are respectively m.
Assuming that the emulsifying and foaming degree is uniform in the whole system, the physicochemical properties of the emulsified liquid drops/foaming foam 2 contained in any point in the system space can be considered to be the same, the imaginary intrinsic point charges 5 generating the distribution of boundary/surface charges are consistent, the emulsified liquid drops/foaming foam 2 is taken as the symmetrical center according to the principle that the electrostatic force 21 applied to the symmetrical center by the symmetrical space point is reversely counteracted, and the resultant force of the electrostatic force 21 generated by the emulsified liquid drops/foaming foam 2 at the central position of the boundary/surface charges formed by co-adsorption of the multicomponent 3 in the hexahedron is formed by taking the intersection point of the three boundaries closest to the boundary of the oil-gas-water emulsifying-foaming system 1 as the corner point.
In fig. 1, view C is a schematic diagram of space attribute subdivision of the oil-gas-water emulsification-foaming system 1, taking the emulsified liquid droplets/foaming foam 2 as a geometric center, taking the 3 nearest basal planes of the oil-gas-water emulsification-foaming system 1 as geometric boundaries, thereby forming a hexahedral boundary of a dead space 10 with mutually offset mechanical effects, and the rest of the space of the oil-gas-water emulsification-foaming system 1 is an effective space 9 with mechanical contribution to the emulsified liquid droplets/foaming foam 2, in addition, according to the contact mode of the effective space 9 and the dead space 10, the effective space 9 can be further divided into 3 categories of a face space 11, a line space 12 and a point space 13, and meanwhile, the boundary of the effective space 9, which is separated by the dead space 10, is also divided into 7 hexahedral subspaces D, E, F, H, I, G, J, wherein the face space 11 with a common contact surface with the dead space 10 comprises subspaces D, E, F; line space 12, which has a common contact edge with dead space 10, includes subspace H, I, G; the dot space 13 having a common contact point with the dead space 10 has only the subspace J.
Therefore, the oil-gas-water emulsification-foaming system space is defined as an effective space 9 and an ineffective space 10 so as to distinguish the contribution degree of the charge distribution of any space point interface/surface film 4 to the mechanical action of the description object, so as to obtain a 1 ≥a 2 ,b 1 ≤b 2 ,c 1 ≥c 2 For example, six boundaries of dead space 10 may be represented as:
furthermore, the effective space 9 can be further divided into a planar space 11, a line space 12, and a dot space 13, which are equal to x, in such a manner that the effective space 9 contacts the ineffective space 10 1 ＝a 2 The planes are in contact, and the boundary of the face space 11 with the planes as contact interfaces is:
the geometric center and volume of this face space 11 are expressed as:
V A ＝4(a 1 -a 2 )c 2 b 1
wherein A is the same as x 1 ＝a 2 Geometrical center coordinates of the contacted surface space; v (V) A For this spatial volume of face space, m 3 。
Similarly, obtain and respectively match y 1 ＝-b 1 、z 1 ＝c 2 The geometric center and volume expression of the planar contact face space 11 are as follows:
V B ＝4a 2 (b 2 -b 1 )c 2
V C ＝4a 2 b 1 (c 1 -c 2 )
the same method is used for respectively acquiring and connecting
The geometric center and volume expression of the line space 12 where the space lines are in contact is as follows:
V D ＝2(a 1 -a 2 )(b 2 -b 1 )c 2
V E ＝2(a 1 -a 2 )b 1 (c 1 -c 2 )
V F ＝2a 2 (b 2 -b 1 )(c 1 -c 2 )
acquisition and spatial point (a) 2 ,-b 1 ,c 2 ) The geometric center and volume of the contacted point space 13 are expressed as:
V G ＝(a 1 -a 2 )(b 2 -b 1 )(c 1 -c 2 )
thereby completing the acquisition of the attribute parameters of the oil-gas-water emulsification-foaming system space.
And repeating the steps to finish the acquisition of the spatial attribute parameters of the oil-gas-water emulsification-foaming system with the other property.
Fourthly, establishing a vector form of electrostatic force between interface/surface charges in the oil-gas-water emulsification-foaming system;
the interface/surface charges existing in the effective space 9 of the oil-gas-water emulsification-foaming system 1 can generate an external electric field by taking the interface/surface charges as a center, the vector superposition acts on the emulsified liquid drops/foaming foam 2, and the formed electrostatic force 21 has the definition formula:
in which Q 1 The charge quantity is the forced charge, C; q (Q) 2 The amount of charge, C, being the forced charge; r is the action distance between two charges, m; epsilon rc To emulsify the relative dielectric constant of the continuous phase around the droplet/frothed foam.
The charge-volume coefficient is defined in consideration of randomness of the morphological size and distribution density of the emulsified liquid drops/foaming foam 2 in the oil-gas-water emulsification-foaming system 1
Reflecting the different types of total charge in the active space 9 are:
wherein the dead space centered on the emulsified liquid droplets/frothing foam is taken as the reference space, i.e. V 0 ＝8a 2 b 1 c 2 V is the space volume of any effective space in the oil-gas-water emulsification-foaming system, m 3 The method comprises the steps of carrying out a first treatment on the surface of the Q is the total charge of any effective space, C; v (V) 0 Is the space volume, m of a reference space in an oil-gas-water emulsification-foaming system 3 ；Q 0 For this reference space corresponds to the reference charge amount, C.
Meanwhile, based on the average particle size of the oil-gas-water emulsification-foaming system 1, the volume ratio of the reference space to the total space is combined to construct the space distribution density of the emulsified liquid drops/foaming foam 2, and then the reference charge and the virtual intrinsic point charge 5 are related to each other by the following steps:
Wherein phi is the volume ratio of the disperse phase of the oil-gas-water emulsification-foaming system.
The charge-to-volume coefficient and the reference charge are introduced into the electrostatic force 21 by the definition:
from which the electrostatic force coefficient ζ is extracted with respect to the effective space 9 attribute parameter:
according to the determination of the geometric center coordinates and the volume of the face space 11 in the step (three), substituting the definition of electrostatic force coefficients to obtain:
since the electrostatic force 21 is the vector superposition of all the effective spaces 9 to the electrostatic force components of the emulsified liquid droplets/foaming foam 2, and the directions of the electrostatic forces 21 generated by the different types of effective spaces 9 are different, in order to uniformly characterize the vector properties of the electrostatic forces 21 corresponding to the surface space 11, the line space 12 and the point space 13, the X, Y, Z axial direction of the three-dimensional rectangular coordinate system is selected as the base vector, and then the direction vector pointing to the origin from the geometric center in the surface space 11 can be expressed as:
to eliminate the influence of the modulo of the direction vector on the magnitude of the electrostatic force 21, the conversion of the direction vector into a unit vector has:
considering that the direction unit vector has base vectors of 3 directions, the electrostatic force coefficient ζ is also spread along the directions of the 3 base vectors, and the electrostatic force coefficient vectors of the different face spaces 11 are constructed by combining the unit vectors:
Wherein:
is a base vector in the X-axis direction; />
Is a base vector in the Y-axis direction; />
Is a base vector in the Z-axis direction.
The expression of algebraic form of electrostatic force 21 is combined, the electrostatic force 21 of all the face spaces 11 is subjected to vector superposition, and the vector form of the electrostatic force 21 is converted into:
similarly, the electrostatic force 21 vector form of the line space 12 can be obtained respectively
And the electrostatic force 21 vector form of the dot space 13 +.>
Thus, the vector form construction of the interfacial/surface electrostatic force in the oil-gas-water emulsification-foaming system is completed.
Repeating the step to complete the electrostatic force vector form construction of the oil-gas-water emulsifying-foaming system with the other property.
(V) determining the distribution of interfacial/surface charges taking into account the tangential mechanical balance of the emulsified liquid droplets/frothed foam;
in the oil-gas-water emulsification-foaming system 1, the force analysis is carried out on the emulsified liquid drop/foaming foam 2, the force acting on the interface/surface film 4 comprises the interface/surface tension 16 which keeps the interface/surface film 4 continuously existing, the shearing force 20 generated by the shearing flow field 14, the electrostatic force 21 of interface/surface charge interaction, the gravity 19 and the buoyancy 18 caused by oil-water density (difference) and the additional pressure 17 caused by the pressure difference between the inside and the outside of the interface/surface film 4, and the force balance analysis is carried out on the interface/surface film 4 micro-element 15 with the area dA.
Fig. 2 is a partial enlarged view of fig. 1 in the present invention, which provides a stress analysis of the microcell 15 of the middle section 7 of the emulsified liquid droplet/frothing foam 2 under the action of the shear flow field 14, as shown in fig. 2, for the fully deformed and balanced interface/surface film 4, the microcell 15 is taken, the two side sections of the microcell 15 are subjected to symmetrical interface/surface tension 16, additional pressure 17 is generated due to internal and external pressure differences in the normal direction, the volume and mass of the microcell 15 in the vertical direction will cause gravity 19 and buoyancy 18, and meanwhile, in consideration of the existence of the external shear flow field 14, a shear force 20 is formed in the tangential direction of the microcell 15, and a steering angle 22 is induced on the basis of the shear deformation of the emulsified liquid droplet/frothing foam 2. Furthermore, due to the charge distribution on the interface/surface film 4 of the emulsified liquid droplet/frothing foam 2, the micro-element 15 will also be subjected to the electrostatic forces 21 exerted by the effective space 9, such that the micro-element 15 reaches a static equilibrium.
The additional pressure 17 can be balanced out against the resultant force of the interfacial/surface tension forces 16 acting on both sides of the microcell body 15 according to Young-Laplace's theorem. Since the area of the micro-element 15 is approximately 0, the micro-element 15 can be regarded as a hexahedron, and the gravity 19 and the buoyancy 18 received by the micro-element can be expressed as:
G＝ρ d gδdA
F f ＝ρ c gδdA
Wherein ρ is d For density of disperse phase in oil-gas-water emulsification-foaming system, kg/m 3 ；ρ c For density of continuous phase in oil-gas-water emulsification-foaming system, kg/m 3 。
When the oil-gas-water emulsification-foaming system 1 is positioned in the shear flow field 14, the interface/surface film 4 of the emulsified liquid drop/foaming foam 2 is subjected to the action of the shear force 20, so that the emulsified liquid drop/foaming foam 2 is affine deformed into a stable elliptic shape, and the deformation characteristics of the emulsified liquid drop/foaming foam 2 when the emulsified liquid drop/foaming foam 2 is formed into elliptic shapes with different radius distributions under the shearing action of different flow fields are as follows:
in the method, in the process of the invention,
d is the deformation degree of the emulsified liquid drop/foaming foam under the shearing action of a flow field; alpha is the steering angle and rad synchronously induced when the emulsified liquid drops/foaming foam deform under the shearing action of a flow field; f is a viscous shear stress revealing stretching of the emulsified liquid droplets/frothed foamA coefficient of competition mechanism with interfacial/surface tension maintaining the emulsified droplet/frothed foam shape; lambda is the viscosity ratio of the dispersed phase to the continuous phase; a and b are respectively the long axis length and the short axis length of the deformed ellipsoidal oil-water emulsion liquid drop/foaming foam, and m; mu (mu) d Is the viscosity of the disperse phase, pa.s; mu (mu) c Viscosity of continuous phase, pa.s; τ is flow field shear stress, pa; d is the equivalent particle diameter of emulsified liquid drops/foaming foam before deformation in an oil-gas-water emulsification-foaming system, and m; v is the interfacial tension, N/m.
Assuming that the oil-gas-water emulsification-foaming system 1 is an incompressible fluid, according to the principle of mass conservation, the volumes of the sphere and the ellipsoid before and after deformation are equal, and the particle size of the spherical emulsified liquid drops/foaming foam 2 before shearing deformation is obtained by a volume formula of the sphere and the ellipsoid is as follows:
considering the geometrical characteristics of affine deformation, the deformation difference of the emulsified liquid drop/frothing foam 2 on the normal plane of the flow direction of the shear flow field 14 is very small, namely b=c, and then the geometrical equation of the combined ellipsoid is that the shear force 20 and tangential direction vector are extracted from the deformation characteristics:
in the method, in the process of the invention,
τ is the shear stress applied by the external shear flow field to the interface/surface film, pa; />
Units of the direction of action of the shear stress thereforVector.
Taking the dynamic stability of the maximum deformation place of the ellipsoidal middle section 7 of the emulsified liquid drop/foaming foam 2 as a balance condition, carrying the surface charge of the micro-element 15 of the interface/surface film 4 into the vector form of the electrostatic force 21 of the interface space 11 in the step (four), and combining the steering angle 22 to obtain the tangential projection of the electrostatic force 21 of the interface space 11 on the interface/surface film 4 as follows:
extracting attribute parameters related to the effective space 9 from the tangential projection of the electrostatic force 21 as defined by the electrostatic force coefficients in the step (four), and obtaining electrostatic force tangential coefficients of the face space 11 as follows:
Similarly, the electrostatic force tangential coefficients ζ of the line space 12 and the dot space 13 are obtained respectively 2τ 、ζ 3τ And the tangential decomposition of gravity 19 and buoyancy 18 along the boundary/surface film 4, combined with shear force 20 corresponding to deformation characteristics, brings in boundary/surface charge distribution correlation of step (two) in electrostatic force 21, and constructs a tangential force equilibrium equation comprising:
in zeta 1τ 、ζ 2τ 、ζ 3τ Electrostatic force tangential coefficients of the face space, the line space, and the point space, respectively.
The elimination of the area term dA of the primordial 15 in this equilibrium equation, then satisfies the imaginary intrinsic point charge 5 values for the tangential mechanical equilibrium of the emulsified liquid droplets/frothing foam 2 as:
further, the virtual intrinsic point charge 5 is substituted again into the correlation of the boundary/surface charge distribution in the step (two), and a specific quantitative expression of the boundary/surface charge distribution is obtained:
this completes the determination of the interfacial/surface film charge distribution taking into account the tangential mechanical balance of the emulsified liquid droplets/frothed foam.
By repeating the technical schemes (II), (III), (IV) and (V), the interface/surface mechanical response characteristics of another co-adsorption environment, another shear flow field characteristic or another property oil-gas-water emulsification-foaming system can be determined, so that the interface/surface charge distribution is determined by considering the morphological characteristics of emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system with co-adsorption of different multi-component.
The invention is mainly a five-step method, namely, effective electric field model construction considering the morphological characteristics of emulsified liquid drops/foaming foam, association of boundary/surface charge distribution and virtual internal point charges under the multi-component co-adsorption action, attribute parameter acquisition of oil-gas-water emulsification-foaming system space, vector form construction of electrostatic force between boundary/surface charges in the oil-gas-water emulsification-foaming system, and boundary/surface charge distribution determination considering tangential force balance of emulsified liquid drops/foaming foam, wherein one step and two steps are to construct equivalent conversion relation between boundary/surface charges and polarization charges under the multi-component co-adsorption action according to the morphological characteristics of emulsified liquid drops/foaming foam; 3. the four steps are breaking through the inconvenience brought to operation due to the micro randomness of the co-adsorption effect and the distribution density of the emulsified liquid drops/foaming foam, dividing the spatial attribute of the oil-gas-water emulsification-foaming system according to the contribution degree of the mechanical effect, simultaneously defining and extracting the charge-volume coefficient by the electrostatic force, combining the electrostatic force effect under the macroscopic state with the imaginary internal point charge in the microscopic scale, thereby constructing the electrostatic force vector form acting on the boundary/surface film micro-element, which is also the key for determining the boundary/surface charge distribution in the oil-gas-water emulsification-foaming system; and fifthly, reflecting the mechanical response description of the deformation balance state of the interface/surface film of the emulsified liquid drop/foaming foam, fully considering the synergistic effect of the electrostatic force action between the external shearing flow field and the interface/surface charge on the deformation characteristics of the emulsified liquid drop/foam, constructing a mechanical model of the interface/surface film micro-element in the oil-gas-water emulsification-foaming system, solving the imaginary intrinsic point charge by combining the tangential mechanical balance equation of the interface/surface film micro-element, and determining the interface/surface charge distribution in the oil-gas-water emulsification-foaming system. The method provides a reliable means and scientific method for quantitative description of interface/surface charge distribution in oil-gas-water emulsification-foaming system of any multicomponent co-adsorption environment and any shearing characteristic flow field, and has a pushing effect on promotion and application of chemical flooding oil extraction technology represented by ternary composite flooding in oil field development, promotion of the problem of exacerbation of emulsification degree and foaming behavior of produced liquid caused by breaking multicomponent co-adsorption behavior, and positive effect on formation of ground engineering technology series in intelligent oil field construction and green development and construction of oil field under 'double carbon' target.
Claims (6)
1. A method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system comprising the steps of:
step one, constructing an effective electric field model considering the morphological characteristics of emulsified liquid drops/foaming foam; assuming that the interface/surface film is stretched to be in an ellipsoid shape under the action of a shearing flow field, establishing a three-dimensional coordinate system, setting an imaginary intrinsic point charge at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam, introducing a spherical electric field, intercepting a curve on the ellipsoid surface through an XOY plane, and introducing an effective electric field of any micro-element vertical normal direction of the spherical electric field on the curve:
wherein E is the electric field intensity of the measuring point; epsilon rd The relative dielectric constant of the emulsified liquid droplets/frothed foam; a is the half axis length of the emulsified liquid drop/foaming foam in the X axis direction; b is the half axis length of the emulsion droplet/foam in the Y axis direction; c is half of the emulsion droplet/foam in the Z-axis directionAn axial length; z 0 Is the height of the intercepting plane; beta is an included angle formed by the direction of the electric field diverged from the center of the ellipsoid and the normal line of any point on the boundary/surface film; k=9.0×10 9 N·m 2 /C 2 The method comprises the steps of carrying out a first treatment on the surface of the q is the charge amount of the virtual intrinsic point charge;
establishing the relationship between boundary/surface charge distribution and virtual intrinsic point charge under the multicomponent co-adsorption effect: taking the infinitesimal body with the area dA of any point on the interface/surface film, wherein the capacitance of any infinitesimal body of the whole interface/surface film is equal everywhere, and the interface/surface charge distribution is related to the imaginary intrinsic point charge:
Wherein δ is the interfacial/surface film thickness; c (C) bi Is the measured capacitance of the interfacial/surface film formed corresponding to the fraction of the constituent molecules; s is the interfacial/surface film area through which the current passes;
step three, obtaining attribute parameters of an oil-gas-water emulsification-foaming system space; according to the space position of the emulsified liquid drop/foaming foam, setting the origin of a three-dimensional space rectangular coordinate system at the geometric center of the emulsified liquid drop/foaming foam, constructing a simplified hexahedral space boundary of an oil-gas-water emulsification-foaming system, defining the space of the oil-gas-water emulsification-foaming system as an effective space and an ineffective space, and further dividing the effective space into a face space, a line space and a point space, thereby obtaining attribute parameters of the space of the oil-gas-water emulsification-foaming system;
establishing a vector form of electrostatic force between interface/surface charges in an oil-gas-water emulsification-foaming system;
determining the distribution of interfacial charges/surface charges considering tangential mechanical balance of emulsion droplets/foaming foam, and using the distribution to disclose multi-component aggravated oil-gas-water emulsification and foaming behavior in different production nodes of oil-gas field ground gathering and transportation treatment, so as to realize efficient demulsification and separation treatment of an oil-gas-water emulsification-foaming system of tertiary oil recovery of an oil field;
Epsilon in the above rc A relative dielectric constant of the continuous phase surrounding the emulsified liquid droplets/frothed foam; phi is the volume ratio of the disperse phase of the oil-gas-water emulsification-foaming system; ρ d The density of the disperse phase in the oil-gas-water emulsification-foaming system; ρ c Is the density of the continuous phase in the oil-gas-water emulsification-foaming system; a, a 2 The absolute value of coordinates of vertexes at two ends of the boundary on the negative half axis of the X axis is given by m; b 1 The absolute value of positive semi-axis coordinates of vertexes at two ends of the boundary in the Y axis is given in m; c 2 The absolute value of coordinates of vertexes at two ends of the boundary on a negative half axis of the Z axis is given by m; d is equivalent particle diameter before deformation of emulsified liquid drops/foaming foam in the oil-gas-water emulsification-foaming system; v is the interfacial/surface tension;
μ c viscosity of continuous phase, unit is Pa.s; mu (mu) d Viscosity of the disperse phase is expressed as Pa.s; g is gravitational acceleration.
2. The method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system according to claim 1, wherein: the specific method of the first step is as follows:
an imaginary intrinsic point charge is introduced into the emulsion liquid drop/foaming foam, so that the polarization charge generated by the polarization of the interface/surface film is equivalent to the free charge formed by the co-adsorption of the multicomponent components, and the equilibrium effect of mechanical response is consistent;
Assuming that the boundary/surface film is stretched to be in an ellipsoid shape under the action of a shearing flow field, a three-dimensional coordinate system is established, an imaginary intrinsic point charge is arranged at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam so as to enter a spherical electric field, for any point on the boundary/surface film, the included angle formed by the direction of the electric field diverged by the ellipsoid center and the normal line of the point is beta, and the spherical electric field strength of the imaginary intrinsic point charge at the center of the ellipsoid-shaped emulsified liquid drop/foaming foam is:
wherein E is the electric field intensity of the measuring point, and the unit is V/m; k is an electrostatic force constant, k=9.0×10 9 N·m 2 /C 2 The method comprises the steps of carrying out a first treatment on the surface of the q is the charge amount of the virtual intrinsic point charge, and the unit is C; r is the distance between the field source point charge and the measuring point, and the unit is m; epsilon rd The relative dielectric constant of the emulsified liquid droplets/frothed foam;
then the curve equation on the ellipsoid taken through the XOY plane is:
wherein a is the half axis length of the emulsified liquid drop/foaming foam in the X-axis direction, and the unit is m; b is the half axis length of emulsion liquid drop/foam in the Y axis direction, and the unit is m; c is the half axis length of the emulsion droplet/foam in the Z axis direction, and the unit is m; z 0 The unit is m for the height of the intercepting plane;
converting ellipsoidal curved surface equation into hidden function form includes:
then any point (x, y, z) on the curve taken in the XOY plane 0 ) The normal vector body form of (c) is expressed as:
according to the coordinate expression form of the vector included angle, the normal vector is obtained
And straight line vector->
The cosine value cos beta of the formed projection angle is as follows:
the effective electric field of the vertical normal direction of any microelement body of the introduced spherical electric field on the curve:
3. a method of determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system according to claim 2, wherein: the specific method of the second step is as follows:
taking a micro-element body with the area of any point dA on the interface/surface film, combining the geometric characteristics of extremely small thickness of the interface/surface film, and considering the micro-element body as a plane polar plate, and meanwhile, assuming that the components of the interface/surface film are uniform, namely the self capacitance of any micro-element body of a complete interface/surface film is equal everywhere, according to the capacitance determination, the micro-element body has:
wherein ε r The relative dielectric constant of the medium between the capacitor plates; s is the facing area of the capacitor plate, and the unit is m 2 ，d s The distance of the capacitor electrode plate is m; k is coulomb constant, the unit is N.m 2 /C 2 ；
The microbody capacitance for different co-adsorption environments is expressed as:
wherein C is i The unit of the capacitance value of the lower boundary/surface membrane micro-element relative to the molecular stacking fraction of a certain component is F; c (C) bi Is the measurement capacitance of the interface/surface film formed by the components and the molecular stacking fraction of the components, and the unit is F; s is the area of the interface/surface film passing through the current, the unit is m 2 The method comprises the steps of carrying out a first treatment on the surface of the dA is the area of the primordial volume;
under the action of effective electric field of virtual internal point charges in emulsified liquid drop/foaming foam, the polarized charges generated by molecular polarization should be equivalent to the interface/surface charges, and are determined by capacitance values of interface/surface films, and according to the definition of parallel plate capacitance, the polarized charges are as follows:
where u=e ⊥ Delta, Q is the charge quantity on the parallel plate electrode plate, and the unit is C; u is the pressure difference of the polar plates, and the unit is V; delta is the interface/surface film thickness in m;
then, in combination with the defined relationship between the total charge amount and the charge distribution density, the capacitance of the simultaneous micro-element is expressed as:
wherein sigma is the charge distribution density of the micro-element body, and the unit is C/m 2 ；
Meanwhile, substituting the effective electric field constructed in the first step to obtain a correlation formula of boundary/surface charge distribution and virtual intrinsic point charge:
4. a method of determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system according to claim 3, wherein: the specific method of the third step is as follows:
the distribution probability of emulsified liquid drops/foaming foam existing in the oil-gas-water emulsification-foaming system at any position in the system space is random, and the origin of a three-dimensional rectangular coordinate system is arranged at the geometric center of the emulsified liquid drops/foaming foam according to the space position of the emulsified liquid drops/foaming foam, so that the simplified hexahedral space boundary of the oil-gas-water emulsification-foaming system is constructed as follows:
Wherein a is 1 +a 2 ＝l a ，l a The unit of the length of the oil-gas-water emulsification-foaming system along the X-axis boundary is m; a, a 1 、a 2 The absolute values of coordinates of vertexes at two ends of the boundary at the positive half axis and the negative half axis of the X axis are respectively shown in m; b 1 +b 2 ＝l b ，l b The length of the oil-gas-water emulsification-foaming system along the Y axis is m; b 1 、b 2 The absolute values of coordinates of vertexes at two ends of the boundary at a positive half axis and a negative half axis of the Y-axis are respectively shown in m; c 1 +c 2 ＝l c ，l c The length of the oil-gas-water emulsification-foaming system along the Z axis is m; c 1 、c 2 The absolute values of coordinates of vertexes at two ends of the boundary at a positive half axis and a negative half axis of the Z axis are respectively shown in m;
assuming that the emulsification and foaming degree is uniform in the whole oil-gas-water emulsification-foaming system, if the physicochemical properties of emulsified liquid drops/foaming foams contained in any point in the system space are the same, the virtual intrinsic point charges generating boundary/surface charge distribution are consistent, and according to the principle that electrostatic force applied to a symmetrical center by a symmetrical space point is reversely counteracted, the emulsified liquid drops/foaming foams are taken as the symmetrical center, and the resultant force of electrostatic force generated by the emulsified liquid drops/foaming foams at the central position of all boundary/surface charges in a hexahedron formed by taking the boundary intersection point closest to the boundary of the oil-gas-water emulsification-foaming system as the corner point is zero;
The space of the oil-gas-water emulsification-foaming system is defined as effective space and ineffective space to distinguish anyThe degree of contribution of the boundary/surface film at the point to the mechanical action of the descriptive object is defined as a 1 ≥a 2 ,b 1 ≤b 2 ,c 1 ≥c 2 For example, six boundaries of dead space are expressed as:
the effective space is further divided into a face space, a line space and a point space according to the contact mode of the ineffective space and the effective space, wherein x is the same as that of the effective space 1 ＝a 2 The planes are contacted, and the boundary of the surface space taking the planes as contact interfaces is as follows:
the specific expression of the geometric center and volume of the space is:
V A ＝4(a 1 -a 2 )c 2 b 1
wherein A is the same as x 1 ＝a 2 Geometrical center coordinates of the contacted surface space; v (V) A For this purpose the spatial volume of the face space is given in m 3 ；
Similarly, obtain and respectively match y 1 ＝-b 1 、z 1 ＝c 2 The geometric center and volume expression of the planar-contacted surface space are as follows:
V B ＝4a 2 (b 2 -b 1 )c 2
V C ＝4a 2 b 1 (c 1 -c 2 )
the same method is used for respectively acquiring and connecting
The line space geometric center and volume expression of the space straight line contact are as follows:
V D ＝2(a 1 -a 2 )(b 2 -b 1 )c 2
V E ＝2(a 1 -a 2 )b 1 (c 1 -c 2 )
V F ＝2a 2 (b 2 -b 1 )(c 1 -c 2 )
acquisition and spatial point (a) 2 ,-b 1 ,c 2 ) The geometric center and volume of the contacted point space are expressed as follows:
V G ＝(a 1 -a 2 )(b 2 -b 1 )(c 1 -c 2 )。
5. the method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system according to claim 4, wherein: the specific method of the fourth step is as follows:
the interface/surface charge existing in the effective space in the oil-gas-water emulsification-foaming system generates an external electric field by taking the interface/surface charge as a center, the vector superposition acts on emulsified liquid drops/foaming foam, and the formed electrostatic force is defined as follows:
In which Q 1 The unit is C, which is the charge quantity of the forced charge; q (Q) 2 The unit of the charge amount is C; r is the action distance between two charges, and the unit is m; epsilon rc A relative dielectric constant of the continuous phase surrounding the emulsified liquid droplets/frothed foam;
the form size and distribution density of emulsified liquid drop/foaming foam in the oil-gas-water emulsification-foaming system are random, and the charge-volume coefficient is defined
Reflecting the different types of total space charge amounts are:
wherein the dead space centered on the emulsified liquid droplets/frothing foam is taken as the reference space, i.e. V 0 ＝8a 2 b 1 c 2 V is the space volume of any effective space in the oil-gas-water emulsification-foaming system, and the unit is m 3 The method comprises the steps of carrying out a first treatment on the surface of the Q is the total charge of any effective space, and the unit is C; v (V) 0 The unit of the space volume of the reference space in the oil-gas-water emulsification-foaming system is m 3 ；Q 0 The reference charge quantity corresponding to the reference space is given by C;
at the same time, oil-gas-water-based emulsificationThe average particle size of the foaming system, the volume ratio of the reference space to the total space, the space distribution density of the emulsified liquid drops/the foaming foam is constructed, and then the reference charge Q is calculated 0 Associated with the imaginary intrinsic point charge q is:
wherein phi is the volume ratio of the disperse phase of the oil-gas-water emulsification-foaming system;
The charge-to-volume coefficient and the reference charge are introduced into the definition of electrostatic force:
from which the electrostatic force coefficient ζ is extracted with respect to the effective spatial attribute parameter:
substituting the electrostatic force coefficient definition according to the expression of the geometrical center coordinates and the volume of the surface space in the third step to obtain:
because the electrostatic force is that all effective spaces carry out vector superposition on electrostatic force components of emulsified liquid drops/foaming foam, the electrostatic force directions generated by different types of effective spaces are different, and the X, Y, Z axial direction of a three-dimensional rectangular coordinate system is selected as a base vector, the direction vector pointing to the origin from the geometric center in the face space is expressed as:
to eliminate the influence of the modulo of the direction vector on the electrostatic force magnitude, the conversion of the direction vector into a unit vector has:
considering that the direction unit vector has base vectors in 3 directions, the electrostatic force coefficient ζ is expanded along the directions of the 3 base vectors, and the electrostatic force coefficient vectors in different plane spaces are constructed by combining the unit vectors:
wherein:
is a base vector in the X-axis direction; />
Is a base vector in the Y-axis direction; />
Is a base vector in the Z-axis direction;
combining the expression of algebraic forms of electrostatic force, carrying out vector superposition on the electrostatic force of all the surface spaces, and converting the electrostatic force vector forms into:
Similarly, the electrostatic force vector form of the line space can be obtained respectively
And electrostatic force vector form of the dot space +.>
6. The method for determining the multi-component co-adsorption interface/surface charge distribution of an emulsion-foaming system according to claim 5, wherein: the specific method of the fifth step is as follows:
the interface/surface film micro-element body with the area dA is regarded as a hexahedron, and the gravity and buoyancy received by the interface/surface film micro-element body are expressed as follows:
G＝ρ d gδdA
F f ＝ρ c gδdA
wherein ρ is d Is the density of the disperse phase in the oil-gas-water emulsification-foaming system, and the unit is kg/m 3 ；ρ c Is the density of continuous phase in oil-gas-water emulsification-foaming system, and the unit is kg/m 3 ；
When the oil-gas-water emulsification-foaming system is in a shear flow field, the interface/surface film of the emulsified liquid drops/foaming foam can be subjected to the action of a shear force, so that the emulsified liquid drops/foaming foam can be affine deformed into stable ellipsoids, and the deformation characteristics of the emulsified liquid drops/foaming foam formed into ellipsoids with different radius distributions under the shearing action of different flow fields are as follows:
in the method, in the process of the invention,
d is the deformation degree of the emulsified liquid drop/foaming foam under the shearing action of a flow field; alpha is a steering angle synchronously induced when the emulsified liquid drops/foaming foam deform under the shearing action of a flow field, and the unit is rad; f is a coefficient revealing a competing mechanism between viscous shear stress stretching the emulsified liquid droplets/frothed foam and interfacial/surface tension maintaining the emulsified liquid droplet/frothed foam shape; lambda is the viscosity ratio of the dispersed phase to the continuous phase; a is the half axis length of emulsified liquid drop/foaming foam in the X axis direction, and the unit is m; b is the half axis length of emulsion liquid drop/foam in the Y axis direction, and the unit is m; mu (mu) d Viscosity of the disperse phase is expressed as Pa.s; mu (mu) c Viscosity of continuous phase, unit is Pa.s; τ is the shear stress of the flow field, unitPa is the value; d is equivalent particle diameter of emulsified liquid drops/foaming foam before deformation in an oil-gas-water emulsification-foaming system, and the unit is m; v is the interfacial tension in N/m;
assuming that the oil-gas-water emulsification-foaming system is an incompressible fluid, according to the principle of mass conservation, the volumes of the sphere and the ellipsoid before and after deformation are equal, and the spherical emulsified liquid drops/foaming foam particle size before deformation is obtained by a volume formula of the sphere and the ellipsoid:
considering the geometrical characteristics of affine deformation, the deformation difference of the emulsified liquid drop/foaming foam on the normal plane of the flow direction of the shearing flow field is very small, and b=c, the geometrical equation of the simultaneous ellipsoids is adopted, and the shearing stress and tangential direction vectors are extracted from the deformation characteristics:
in the method, in the process of the invention,
τ is the shear stress applied by the external shear flow field to the interface/surface film, and the unit is Pa; />
For this purpose, a unit vector of the direction of action of the shear stress;
the dynamic stability of the maximum deformation of the middle section of the emulsified liquid drop/foaming foam ellipsoid is taken as a balance condition, the surface charge of the interface/surface film microelements is substituted into the vector form of the interfacial space electrostatic force in the fourth step, and the tangential projection of the interfacial space electrostatic force on the interface/surface film is obtained by combining the steering angle:
And according to the definition of the electrostatic force coefficient in the fourth step, extracting geometric parameters related to effective space from the electrostatic force tangential projection to obtain the electrostatic force tangential coefficient of the face space, wherein the electrostatic force tangential coefficient is as follows:
similarly, the electrostatic force tangential coefficients ζ of the line space and the point space are respectively obtained 2τ 、ζ 3τ Further, the gravity and the buoyancy are decomposed along the tangential direction of the boundary/surface film, the shearing force corresponding to the deformation characteristic is combined, meanwhile, the boundary/surface charge distribution correlation of the second step is carried into the electrostatic force, and a tangential mechanics equilibrium equation is constructed, wherein the tangential mechanics equilibrium equation is constructed by the following steps:
in zeta 1τ 、ζ 2τ 、ζ 3τ Electrostatic force tangential coefficients of the face space, the line space, and the point space, respectively;
eliminating the area term dA of the infinitesimal in the balance equation, and meeting the imaginary intrinsic point charge value of tangential mechanical balance of the emulsified liquid drop/foaming foam is as follows:
further, the virtual intrinsic point charge is substituted again into the correlation of the boundary/surface charge distribution in the second step, so as to obtain a specific quantitative expression of the boundary/surface charge distribution:
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