CN108716392A - Viscous fingering optimization method and device in the gravitational effect control surface activating agent displacement of reservoir oil - Google Patents
Viscous fingering optimization method and device in the gravitational effect control surface activating agent displacement of reservoir oil Download PDFInfo
- Publication number
- CN108716392A CN108716392A CN201810485011.1A CN201810485011A CN108716392A CN 108716392 A CN108716392 A CN 108716392A CN 201810485011 A CN201810485011 A CN 201810485011A CN 108716392 A CN108716392 A CN 108716392A
- Authority
- CN
- China
- Prior art keywords
- seepage
- sand
- oil
- physical model
- injection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000000694 effects Effects 0.000 title claims abstract description 95
- 238000006073 displacement reaction Methods 0.000 title claims abstract description 93
- 238000000034 method Methods 0.000 title claims abstract description 58
- 238000005457 optimization Methods 0.000 title claims abstract description 29
- 230000003213 activating effect Effects 0.000 title abstract 3
- 239000004094 surface-active agent Substances 0.000 claims abstract description 159
- 239000004530 micro-emulsion Substances 0.000 claims abstract description 74
- 238000004519 manufacturing process Methods 0.000 claims abstract description 72
- 239000004576 sand Substances 0.000 claims abstract description 30
- 230000000704 physical effect Effects 0.000 claims abstract description 14
- 238000013461 design Methods 0.000 claims abstract description 10
- 230000005484 gravity Effects 0.000 claims description 82
- 238000002347 injection Methods 0.000 claims description 80
- 239000007924 injection Substances 0.000 claims description 80
- 239000000243 solution Substances 0.000 claims description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 45
- 230000035699 permeability Effects 0.000 claims description 38
- 239000003638 chemical reducing agent Substances 0.000 claims description 35
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 34
- 238000005070 sampling Methods 0.000 claims description 22
- 238000000605 extraction Methods 0.000 claims description 20
- 230000008569 process Effects 0.000 claims description 16
- 230000000087 stabilizing effect Effects 0.000 claims description 13
- 230000006872 improvement Effects 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- 230000008859 change Effects 0.000 claims description 9
- 239000012530 fluid Substances 0.000 claims description 8
- 238000003466 welding Methods 0.000 claims description 7
- 230000001133 acceleration Effects 0.000 claims description 6
- 238000004945 emulsification Methods 0.000 claims description 6
- 238000010276 construction Methods 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000005012 migration Effects 0.000 claims description 4
- 238000013508 migration Methods 0.000 claims description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 239000000741 silica gel Substances 0.000 claims description 3
- 229910002027 silica gel Inorganic materials 0.000 claims description 3
- 239000011780 sodium chloride Substances 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- 239000006004 Quartz sand Substances 0.000 claims description 2
- 238000005065 mining Methods 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 abstract description 17
- 238000005516 engineering process Methods 0.000 abstract description 10
- 238000005325 percolation Methods 0.000 abstract description 7
- 239000012190 activator Substances 0.000 abstract 1
- 238000006116 polymerization reaction Methods 0.000 abstract 1
- 230000006399 behavior Effects 0.000 description 29
- 230000007306 turnover Effects 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 8
- 238000011161 development Methods 0.000 description 7
- 238000011084 recovery Methods 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000009412 basement excavation Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 238000005381 potential energy Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000005063 solubilization Methods 0.000 description 2
- 230000007928 solubilization Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241000237858 Gastropoda Species 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The present invention relates to viscous fingering optimization method and devices in the gravitational effect control surface activating agent displacement of reservoir oil, viscous fingering optimization method is followed successively by note and adopts seepage flow dip-adjustable type back-up sand design of physical model wherein in the displacement of reservoir oil of gravitational effect control surface activating agent, gravitational effect lower surface activator solution displacing phase is associated with the percolation flow velocity for forming microemulsion slug interface zone, microemulsion slug is formed under gravitational effect to be associated with the percolation flow velocity of " oily wall " interface zone is promoted, physical model unitary surfactant flooding leading edge and percolation flow physical properties parameter acquiring, gravitational effect stable displacement leading edge removes oil saturation and becomes the division of steady seepage technical limits and the optimization of viscous fingering control ability that note adopts seepage flow inclination angle.The present invention solves in existing surfactant flooding, in order to effectively avoid viscous fingering, the problem of often needing to introduce polymerization species mobility control agent to system and further increase cost for oil production and complicate ground injection-production technology.
Description
The technical field is as follows:
the invention relates to a method and a device for controlling viscous fingering optimization in surfactant flooding oil, which solve the technical problems of how to utilize a gravity-assisted effect to stabilize a displacement front edge and control viscous fingering behavior and how to optimize a surfactant oil production well pattern deployment mode under the gravity-assisted effect when a mobility control agent is absent in the surfactant flooding oil.
Secondly, background art:
although the application of viscoelastic polymer flooding is the most widely used in China, with the continuous coming of the limit of polymer flooding Efficiency and the exploration and development of complex types of oil reservoirs, under the background of virtuous cycle of oil field reserves and output and the demand of ordered succession, the use of a surfactant capable of reducing oil-water interfacial tension, increasing the number of capillary tubes and starting residual oil as a chemical oil displacement agent has become the main countermeasure for slowing down later development and reducing output of oil fields (Wang Yefei, Li Jiyong, Zhuao Fulin, PetroGelogy & Recovery Efficiency), 2001 (1): 67-69; Wang Gang, Wang Demin, Xiifen, Huuye, liu Chunde (liuchunde), Acta Petrolei Sinica (proceedings of petroleums), 2007, 28 (4): 86-90; jun Lu, Ali Goudarzi, Beila Chen, Do Hoon Kim, Mojdeh Delshad, Kishore K.Mohanty, Kamy Sepehriori, Upal P.Weerasoriya, Gary A.Pope, Journal of Petroleumscience and Engineering, 2014, 124: 122-. Besides the synergistic effect of fluidity control and interface activity improvement by assisting with polymers or alkali, the monoprotic surfactant flooding oil also attracts wide attention and research application in the field of tertiary oil recovery like binary compound flooding and ternary compound flooding in recent years. The oil displacement technology has the advantages of greatly simplifying a ground engineering injection system and a production system, saving the cost of extra agent in the combined flooding and relatively reducing the difficulty of the ground treatment of the produced liquid while realizing the removal of oil saturation. Particularly, for medium and high permeability oil reservoirs, the excavation of latent dead-end type residual oil after water flooding or polymer flooding mainly aims at overcoming capillary force, and promoting solubilization, emulsification and carrying (Chen Hailing, Zheng Xiaoyu, Jiang Qingzhe, Modern chemical industry, 2013, 33 (3): 12-16; Zhou Yazhou, Yi Daiyin (Yin mark), Cao Rui, Oilfield Chemistry, 2016, 33 (2): 285-290), so that the mature monoprotic surface oil flooding technology is still one of the sustainable tertiary oil recovery core technologies for improving the utilization rate of non-renewable resources, guaranteeing the development of oil fields and maintaining the national energy safety.
However, the unitary surfactant flooding lacks a mobility control agent represented by a polymer, the viscosity of the aqueous solution of the unitary surfactant flooding is low, the viscous behavior in a heterogeneous oil reservoir is very prominent, and the problem that the displacement front is unstable in advancing and the flooding efficiency of the porous medium heterogeneous seepage process is directly influenced is further caused. Although the large-scale high-speed development and application of the horizontal well technology provide convenient and superior conditions for gravity-assisted oil recovery, related exploratory research (Si Le Van, Bo Hyunchon, Energies, 2016, 9 (4): 244) is also available in a surfactant-involved compound flooding method, how to exert a gravity-assisted effect to control viscous fingering, how to determine seepage parameter boundaries in the gravity-assisted effect exerting process, and how to optimize an oil recovery well pattern deployment mode of a corresponding gravity effect substituted mobility control agent under the change of oil reservoir geological conditions is still a blank, and is also a difficult problem and an urgent problem of popularization and application of the monoprotic surfactant flooding technology. Meanwhile, on one hand, the emulsification of the ultra-low interfacial tension surfactant system and the residual oil inevitably forms a microemulsion slug which isolates a displacement phase from a front end oil wall to a certain extent while reducing the adhesion work and stripping the residual oil to form an oil wall propulsion in the oil displacement process of the ultra-low interfacial tension surfactant, and on the other hand, the inclined shaft technology which can reduce the ground investment of an oil field, is convenient for the ground management of the oil field and is suitable for sidetracking in an old oil well to carry out rolling exploitation is gradually mature, and the method provides feasibility of possible industrial application for a scientific control method which breaks through the limitation of the straight well and the horizontal well in the adjustment of seepage parameter limits, fully considers the microemulsion slug, stabilizes the multiphase seepage characteristic in the surfactant displacement oil by means of the gravity effect and forms the viscous fingering behavior of the multiphase seepage characteristic. Therefore, the invention provides a method for controlling viscosity fingering behavior in surfactant flooding by using gravity effect, and the invention discloses a test device optimized by the method, which has important significance and reference value for designing drilling engineering and formulating flooding scheme in unary surfactant oil extraction, and is beneficial to promoting the industrial popularization work of reducing the saturation of residual oil by unary surfactant flooding in oil fields with high water cut period.
Thirdly, the invention content:
the invention aims to provide a method for optimizing viscosity fingering in a gravity effect controlled surfactant flooding, and the invention also aims to provide a device used in the method for optimizing viscosity fingering in the gravity effect controlled surfactant flooding, which is used for solving the problems that in the existing surfactant flooding, in order to effectively avoid viscosity fingering, a polymer-type mobility control agent is often required to be introduced into a system, so that the oil production cost is further increased, and the ground injection and production process is complicated, and particularly solves the problems that in the exploration application of horizontal wells and inclined wells development technology for stabilizing multiphase seepage of the surfactant flooding by utilizing the gravity effect, the exertion of the gravity stabilizing effect and the control of the viscosity fingering are lack of quantitative association and description.
The technical scheme adopted by the invention for solving the technical problems is as follows: the gravity effect control surface active agent drives the viscous finger to advance the optimization method in the oil:
designing a pouring-mining seepage inclination angle adjustable sand-packed physical model: establishing an original bound water state of a sand-filled physical model compacted according to the hole and seepage parameter requirements and selecting the mesh number and the mixing proportion of quartz sand, driving water to residual oil saturation, obtaining the relative permeability of water phase and the relative permeability of oil phase of the sand-filled physical model, completing the construction of the sand-filled physical model of the residual oil saturation, then placing the sand-filled physical model on a turnover shaft through a slip, wherein one end of the turnover shaft is connected with a rotatable bearing seat, the other end of the turnover shaft is connected with a single-head turbine worm speed reducer, the rotating bearing seat is installed on a supporting frame, an angular displacement transmitter is connected with the single-head turbine worm speed reducer through an input flange bolt, driving the single-head turbine worm speed reducer to obtain power output by using a servo motor with a high-precision code disc, the sand-filled physical model is obliquely arranged, the injection end of the sand-filled physical model is arranged at the lower part and the extraction, the change of the inclination angles of the two ends of the sand-packed physical model is realized, the injection-production seepage inclination angle is measured and controlled by an angular displacement transmitter connected to a single-head turbine worm speed reducer, and the self-locking of the target adjusting inclination angle is realized by the single-head turbine worm speed reducer; meanwhile, in order to obtain physical parameters of fluid in the displacement front edge migration, a sand-packed physical model arranges sampling points along the way from the injection end to the extraction end; completing the design of the injection-production seepage inclination angle adjustable sand-packed physical model;
(II) correlating the surfactant solution displacement phase with the seepage velocity of the microemulsion slug interface region forming by gravity effect: considering that a microemulsion slug is inevitably formed by the emulsification of a surfactant system and residual oil while the adhesion work is reduced and the residual oil is peeled off to form an oil wall propulsion in the monobasic surfactant oil flooding process, dividing a sand-filled physical model porous medium region into a surfactant solution displacement phase region, a microemulsion slug region, an oil wall region and a residual oil zone region from a sand-filled physical model injection end to a production end in the multiphase seepage front propulsion, and constructing a critical interface for controlling the viscous advancing behavior; for the in-path first interface region: the stable seepage velocity expression of the interface region of the surfactant solution displacement phase and the microemulsion slug forming phase in the presence of the associated gravitational effect according to Darcy's law when the interface region has a certain seepage inclination angle:
wherein,
in the above formula: vs-eDisplacing phase for surfactant solution and forming microemulsion slug interfacial regionThe seepage velocity of the domain, m/s; rhosAs the density of the surfactant solution, kg/m3；μsIs the surfactant solution viscosity, Pa.s; mu.seIs microemulsion viscosity, Pa.s; rhoeIs the density of the microemulsion, kg/m3(ii) a K is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; ksRelative permeability of surfactant solution; keRelative permeability of microemulsion; ms-eThe fluidity ratio of the surfactant solution to the microemulsion is defined; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]；
(III) the formation of a microemulsion slug under the effect of gravity is associated with the seepage velocity of the propelling 'oil wall' interface region: second interface region along path with a certain seepage inclination: the micro-emulsion slug and the interface area of the propelled oil wall are associated with the corresponding stable seepage velocity under the gravity effect, and the associated expression is as follows:
however, in the advanced "oil wall", both a mobile oil phase and a mobile water phase exist, and the fluidity of the "oil wall" region is composed of the oil phase fluidity and the water phase fluidity, so that the definition:
in the above formula: ve-oThe seepage velocity of the microemulsion slug and the interface area forming an oil wall is m/s; rhoeIs the density of the microemulsion, kg/m3；ρoIs the density of the oil phase, kg/m3；μeIs microemulsion viscosity, Pa.s; mu.soIs the oil phase viscosity, Pa.s; mu.swIs the viscosity of the water phase, Pa.s; k is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; keRelative permeability of microemulsion; kroIs an oil phaseFor permeability; krwRelative permeability of water phase; me-oThe fluidity ratio of the microemulsion to the oil wall; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]；
(IV) acquiring a monophyletic surfactant flooding front edge and seepage physical property parameters of the physical model: before the sand-filling physical model changes the dip angle of the injection and production end, a unitary surfactant system with known composition properties is injected into the sand-filling physical model of water drive to residual oil saturation, sampling is carried out at on-way sampling points along with the advance of the displacement front edge in sequence, a seepage medium with the maximum sampling viscosity is taken as a microemulsion formed in the unitary surfactant displacement, and the density of a microemulsion slug is synchronously sampled and tested, so that physical parameters corresponding to the known oil phase, the known water phase and the known surfactant solution at the front edge are obtained, wherein the physical parameters comprise rhoo，μo，μw，ρs，μs，ρe，μe(ii) a Meanwhile, when the surfactant has ultralow interfacial activity, the relative permeability of the surfactant solution and the relative permeability of the microemulsion in the multi-phase seepage process can be regarded as 1;
and determining the seepage velocity V of the surfactant solution displacement phase and the formed microemulsion slug interface region under the gravity effect when the dip angle of the injection and production end is changed to a certain seepage dip angle α according to the step (II) and the step (III)s-eAnd the seepage velocity V for forming a microemulsion slug and propelling an oil wall interface areae-o；
Completing the acquisition of the displacement front edge and the seepage physical property parameters;
(V) stabilizing the oil saturation degree of the displacement front edge by gravity effect, namely ensuring that the stable multiphase seepage characteristic is maintained, and obtaining the seepage velocity V of the first interface region and the second interface region along the way when a certain seepage inclination angle α is mets-eAnd Ve-oAnd comparing, taking the smaller value of the two as the stable seepage speed for controlling the viscous fingering, and determining the critical injection flow of the surfactant solution for controlling the viscous fingering according to the following formula:
Q＝A·Vcrit
in the formula: q is the critical injection flow of the surfactant solution, m3S; a is the cross-sectional area perpendicular to the seepage direction, m2；VcritM/s for stable seepage velocity;
according to the critical injection flow of the surfactant solution, after the water flooding residual oil saturation is established in a physical model, a unitary surfactant system with the same property as that in the step (IV) is used for performing constant flow displacement on the model with the injection and production seepage inclination angle α to remove the oil saturation, and the improvement of the oil displacement efficiency is obtained by fully exerting the gravity effect to control the viscous fingering behavior and stabilizing the displacement front edge;
thus, the method construction for controlling the viscosity fingering behavior in the surfactant flooding by the gravity effect is completed;
(VI) stable seepage technical limit division and viscosity fingering control capability optimization of changing injection-production seepage inclination angle, namely changing and adjusting injection-production seepage inclination angle α (α epsilon (0,90 DEG) of sand-pack physical model]) Sequentially determining V at corresponding inclination angless-eAnd Ve-oDividing stable seepage velocity limits when different injection and production seepage dip angles are formed, further establishing a relation between an injection and production seepage dip angle α and a critical injection flow Q of a surfactant solution according to the step (five), and further carrying out gravity effect stable displacement of a front edge to remove oil saturation according to the step (five) on the basis of the relation to obtain oil displacement efficiency improvement values under a series of injection and production seepage dip angles α;
therefore, the stable seepage technical limit division of the variable injection-production seepage inclination angle and the optimization of the control method of the viscous finger are completed.
In the scheme, the steps from the first step (I) to the sixth step (VI) are repeated, the physical property of a sand-filled physical model is changed, or the composition property of a unitary surfactant system is changed, the quantitative relation between the injection and production seepage inclination angle α and the critical injection flow Q of a stable displacement front edge is divided and established when oil reservoirs with different physical properties and different surfactant systems displace oil, and the control capacity of the gravity effect on the viscous finger advancing behavior is optimized and determined by measuring the corresponding oil-removing saturation effect.
In the scheme, the angular displacement transmitter controls the adjustment range of the injection-production seepage inclination angle to be 0-90 degrees, and the adjustment precision is 1 degree.
In the step (III), the relative permeability of the water phase and the relative permeability of the oil phase of the physical model of the filled sand are obtained by adopting an unsteady state method.
In the scheme, when the displacement front and the seepage physical parameters are obtained in the step (IV), the injection speed of the univalent surfactant is 1 m/d.
The device used by the gravity effect control surfactant flooding viscosity finger-entering optimization method comprises an adjustable sand-filling physical model, a piston type oil container, a piston type salt water container, a piston type surfactant solution container, an injection pump, a constant temperature system, a pressure sensor, a collector and an automatic control system, wherein the adjustable sand-filling physical model, the piston type oil container, the piston type salt water container and the piston type surfactant solution container are all arranged in the constant temperature system; the adjustable sand-filling physical model comprises a sand-filling physical model, a support frame, a turnover shaft, a single-head turbine worm speed reducer and an angular displacement transmitter, wherein the sand-filling physical model is arranged on the turnover shaft through a slip, one end of the turnover shaft is connected with a rotatable bearing seat, the other end of the turnover shaft is connected with the single-head turbine worm speed reducer, the rotatable bearing seat is arranged on the support frame, a servo motor with a high-precision code disc is used for driving the single-head turbine worm speed reducer to obtain power output, the angular displacement transmitter is connected to the single-head turbine worm speed reducer through an input flange bolt, the sand-filling physical model is obliquely arranged, an injection end of the sand-filling physical model is arranged below and an extraction end of the sand-filling physical model is arranged above, sampling valves are arranged along the path from the injection;
the piston type oil container, the piston type saline water container and the piston type surfactant solution container are connected in parallel to form a container group, the injection pump is connected with the input end of the container group, the output end of the container group is connected with the sand-filled physical model, the output end of the container group is also provided with a pressure sensor, and the extraction end of the sand-filled physical model is connected with the collector through a silica gel hose;
the single-head worm gear speed reducer, the servo motor, the angular displacement transmitter, the injection pump, the constant temperature system, the pressure sensor, the sampling valve, the control valve and the collector are connected with the automatic control system.
In the scheme, the front end of the collector is provided with a back pressure control unit which is composed of a back pressure pump, a pressure stabilizing tank and a back pressure valve, and the back pressure valve and the back pressure pump are connected with an automatic control system. So as to avoid the end effect caused by potential energy change caused by the change of the dip angle of the injection-production seepage.
The sand physical model is the stainless steel material in above-mentioned scheme, and its diameter 50mm, length 500mm, and the sampling valve who arranges along journey equidistance from its injection end to extraction end is 3.
In the scheme, the reduction ratio of the single-head turbine worm speed reducer is 1:10, and the maximum displacement recognition rate of the servo motor adopting the high-precision code disc is less than 0.02 degrees.
In the scheme, the overturning shaft is connected with the sand-packed physical model at the centers of the overturning shaft and the sand-packed physical model through a slip joint; a triangular welding platform is arranged on the side face of the support frame, and an angle of 45 degrees is formed between the triangular welding platform and the horizontal plane.
Has the advantages that:
the sand-packed physical model is designed to be adjustable in injection-production seepage inclination angle, compared with a horizontal seepage mode, the gravity effect of multi-phase seepage in a porous medium area in the advancing of a displacement front edge can be constructed, a single 90-degree gravity inclination angle is broken through compared with a vertical seepage mode, the injection-production seepage inclination angle is continuously adjustable within the range of 0-90 degrees, the reproduction of the fluid gravity effect in the seepage process is facilitated, the division of the gravity action mechanism of the fluid is also achieved, and the scientific basis is provided for the inclined shaft deployment and design which can exert the gravity auxiliary effect to stabilize seepage.
The invention divides the multiphase seepage area in the advancing of the surfactant oil displacement front edge from the injection end to the extraction end into four areas of a surfactant solution displacement phase, a microemulsion slug, an oil wall and a residual oil zone, scientifically constructs the critical interface of the porous medium seepage area with density difference and fluidity ratio while fully reproducing the influence of the surfactant solution phase behavior on the seepage mechanism in the porous medium, and realizes the necessary physical description for controlling the viscosity fingering behavior in the whole injection and extraction process.
Based on Darcy's law, the invention establishes mathematical expression of stable seepage velocity of different critical interface regions in the advancing of the surfactant flooding oil front edge under the gravity effect by correlating pore seepage parameters, density difference of mobile phase and fluidity ratio, and forms a means for effectively obtaining the displacement front edge and the seepage physical parameters, is convenient for reliably determining the gravity stable seepage velocity of the surfactant solution displacement phase and the microemulsion slug interface area which are formed under different seepage inclination angles and the microemulsion slug interface area which is formed and the oil wall interface area, avoids the condition that the displacement phase is only limited to the surfactant solution and the stable seepage velocity expression is generally established, the density difference between the surfactant solution of the displacing phase and the residual oil zone with high water saturation of the displaced phase is small, so that the problem of a gravity action mechanism can be completely hidden invisibly, and the potential gravity auxiliary effect is beneficial to replace a fluidity control agent to deal with viscous fingering.
And (IV) the invention takes the smaller value of the stable seepage velocity of different critical interface areas as the gravity effect to control the stable seepage velocity of the viscous fingering behavior in the whole injection-production process, and determines the critical injection flow of the surfactant solution at a certain seepage inclination angle, fully considers the multiphase seepage characteristics of different areas of the porous medium under the influence of the phase behavior of the surfactant solution, and ensures that the best full play of the gravity effect-based driving of the monobasic surfactant for stabilizing the front edge and controlling the viscous fingering behavior is ensured.
The invention can divide the technical boundary of the monoprotic surfactant flooding stable seepage when the variable injection-production seepage inclination angle is formed, and quantify the oil saturation removal effect of the corresponding seepage working condition, realizes the optimization of controlling the exertion of the monoprotic surfactant flooding viscosity fingering capability by the gravity effect while adopting the seepage speed boundary to stably displace the front edge, is beneficial to the fine design of the oil extraction mode when the gravity effect is used for replacing a fluidity control agent to improve the monoprotic surfactant flooding multiphase seepage characteristic, and enables the development technology of horizontal wells and inclined wells to obtain quantitative association and description on the exertion of the gravity stabilizing effect and the control of the viscosity fingering behavior.
Sixth, the invention according to surfactant to residual oil solubilization, emulsification and carry and multiphase seepage characteristic and fluid gravity action mechanism correlation in the porous medium, reappear and optimize the gravity effect to control the viscous finger-entering mode in the surfactant flooding, the method is scientific, the principle is clear and feasible, the structure is reasonable, the technical parameter is standard and adjustable, can break through the traditional limitation of using polymer fluidity control agent, effectively provides a method and an optimization device for controlling viscous finger-entering in the surfactant flooding, scientific, operability and practicability are strong, can more fully describe the seepage characteristic of the unitary surfactant flooding in tertiary oil recovery, enrich the principle of the unitary surfactant flooding, provide beneficial scientific method, means and basis, promote the industrial popularization of unitary surfactant flooding in high water-cut oil field to reduce the residual oil saturation, and guides the design of drilling engineering such as inclined wells, horizontal wells and the like and the formulation of an oil displacement scheme in oil extraction.
Fourthly, explanation of the attached drawings:
FIG. 1 is a schematic diagram of the apparatus of the present invention;
fig. 2 is a side view a-a of fig. 1.
Fig. 3 is a top view B-B of fig. 1.
1, a sand-filling physical model 2, a rotary bearing seat 3, a single-head worm gear speed reducer 4, a turnover shaft 5, a servo motor 6, an angular displacement transmitter 7, a support frame 8, a slip joint 9, a triangular welding platform 10, a piston type oil container 11, a piston type saline water container 12, a piston type surfactant solution container 13, an injection pump 14, a constant temperature system 15, a pressure sensor 16, a back pressure pump 17, a pressure stabilizing tank 18, a sampling valve 19, a back pressure valve 20, a control valve 21, a collector 22 and an.
The fifth embodiment is as follows:
the invention is further described below with reference to the accompanying drawings:
as shown in figure 1, the device used by the gravity effect control surface active agent oil flooding viscosity fingering optimization method comprises a sand filling physical model 1 which is made of stainless steel and has the diameter of 50mm and the length of 500mm and is connected with a turnover shaft 4 through a slip joint 8, wherein one end of the turnover shaft 4 is fixed on a rotary bearing seat 2 on a support frame 7 through a bolt, the other end of the turnover shaft is connected with a single-head turbine worm speed reducer 3 on a triangular welding platform 9 with the side surface of the support frame 7 and the horizontal plane forming an angle of 45 degrees, the single-head turbine worm speed reducer 3 is driven when outputting power, so that the sand filling physical model 1 is carried to rotate downwards at an injection end and upwards at a production end to realize the change of the dip angle of the injection and production end, the reduction ratio of the single-head turbine worm speed reducer 3 is 1:10, the power output is driven by a servo motor 5 which is connected with the single-head turbine worm, and the angular displacement transmitter 6 which is connected with the single-head worm and gear speed reducer 3 through an input flange bolt measures the real inclination angle of the sand-packed physical model 1, and when the inclination angle is adjusted to the target, the inclination angle is fixed by closing the servo motor 5 and self-locking the single-head worm and gear speed reducer 3, so that the injection-production seepage inclination angle adjustable sand-packed physical model is integrally formed. Meanwhile, in order to obtain physical parameters of fluid in the migration of the displacement front, 3 sampling valves 18 are arranged in the sand-packed physical model 1 at equal intervals from the injection end to the production end. The piston type oil container 10, the piston type salt water container 11 and the piston type surfactant solution container 12 which are connected with the injection pump 13 and the sand-packed physical model 1 through the control valve 20 are placed in the constant temperature system 14 together with the sand-packed physical model 1, and the extraction end of the sand-packed physical model 1 is connected with the collector 21 through a silica gel hose. The pressure sensor 15 is used for measuring the on-way pressure drop from the injection end to the extraction end, and in order to avoid the end effect caused by potential energy change due to the change of the injection-extraction seepage inclination angle, a back pressure control unit which is jointly formed by a back pressure pump 16, a pressure stabilizing tank 17 and a back pressure valve 19 is arranged at the front end of the collector 21. The single-head worm and gear speed reducer 3, the servo motor 5, the angular displacement transmitter 6, the injection pump 13, the constant temperature system 14, the pressure sensor 15, the sampling valve 18, the back pressure valve 19, the control valve 20 and the collector 21 are all connected with the automatic control system 22, so that the automatic measurement and control of parameters and operation are realized.
FIG. 2 and FIG. 3 are a side view and a top view of A-A of FIG. 1, which provide schematic structural views for realizing the adjustment of the injection-production seepage inclination angle of the sand-packed physical model 1, as shown in the figures, a single-head turbine worm reducer 3 is arranged on a triangular welding platform 9 which forms an angle of 45 degrees with the horizontal plane on the side surface of a support frame 7, the output end of a servo motor 5 is butted with an inner bearing of the single-head turbine worm reducer 3 to realize power transmission, one end of a turning shaft 4 which is connected with the sand-packed physical model 1 through a slip joint 8 is fixed with a rotary bearing seat 2 on the support frame 7 through a bolt, the other end is connected with the single-head turbine worm reducer 3, so as to ensure that the sand-packed physical model 1 is driven to rotate when the power is driven, and simultaneously ensure the flexibility of the rotation and the rotation angle, an angular displacement transmitter 6 which is embedded in the single-head controllable turbine, and converting the rotation angle into an electric signal for output, and ensuring that the injection-production seepage inclination angle of the sand-packed physical model 1 is continuously adjustable within the range of 0-90 degrees according to the adjustment precision of 1 degree.
The invention discloses a method for optimizing viscous fingering in oil flooding controlled by gravity effect, which comprises the steps of designing a sand-packed physical model with adjustable injection and production seepage dip angles, associating a surfactant solution displacement phase under the gravity effect with a seepage velocity forming a microemulsion slug interface area, associating the formed microemulsion slug with the seepage velocity of a propelling oil wall interface area under the gravity effect, acquiring a monobasic surfactant flooding front edge and seepage property parameters of the physical model, dividing a stable seepage technical limit of removing oil saturation of the gravity effect stable flooding front edge and changing the injection and production seepage dip angles, and optimizing the viscous fingering control capability. The method comprises the following specific steps:
and (I) designing a pouring and production seepage inclination angle adjustable sand filling physical model. Starting a constant temperature system 14, communicating an injection pump 13 and a piston type oil container 10, establishing an original bound water state of a sand-filled physical model 1 compacted according to hole and seepage parameter requirements and a mixing proportion, driving the injection pump 13 to replace a piston type brine container 11 to drive water to residual oil saturation by switching a control valve 20, obtaining the relative permeability of water phase and the relative permeability of oil phase of the model, connecting the sand-filled physical model 1 with the built residual oil saturation to a rotatable bearing seat 2 fixed on a support frame 7 at one end through a slip joint 8, connecting the other end to an overturning shaft 4 of a single-head worm gear reducer 3, then driving the single-head worm gear reducer 3 to obtain power output by using a servo motor 5 with a high-precision code disc, and then rotating the sand-filled physical model 1 to different degrees by the downward direction of an injection end and the upward direction of an extraction end, the change of the dip angle of the injection-production end of the sand-packed physical model 1 is realized, the dip angle of the injection-production seepage is measured and controlled by an angular displacement transmitter 6 connected to a single-head worm gear reducer 3, and the self-locking of the target dip angle adjustment is realized by the single-head worm gear reducer 3. Meanwhile, in order to obtain physical parameters of fluid in the migration of the displacement front, 3 sampling valves 18 are arranged in the sand-packed physical model 1 at equal intervals from the injection end to the production end. Thus, the design of the injection-production seepage inclination angle adjustable sand-packed physical model 1 is completed.
And repeating the construction of the residual oil saturation in the step, and designing another injection-production seepage inclination angle adjustable sand-filling physical model with another physical property.
And (II) in view of the facts that in the process of driving the oil by the unary surfactant, when the adhesion work is reduced and the residual oil is peeled off to form an oil wall, a micro-emulsion slug is inevitably formed by emulsification of a surfactant system and the residual oil, in the process of driving the multiphase seepage front, a model porous medium area is divided into a surfactant solution displacement phase area, a micro-emulsion slug area, an oil wall area and a residual oil zone area from a filling end to a production end, and a critical interface for controlling the viscous driving behavior is constructed. For the first interfacial region along the way, i.e. the interfacial region of the surfactant solution displacement phase and the microemulsion slug formation, the steady percolation velocity expression of this interfacial region in the presence of the associated gravitational effect, according to darcy's law, at a certain percolation inclination angle, is:
wherein,
in the above formula: vs-eThe seepage velocity m/s is the seepage velocity of a surfactant solution displacement phase and a formed microemulsion slug interface area; rhosAs the density of the surfactant solution, kg/m3；μsIs the surfactant solution viscosity, Pa.s; mu.seIs microemulsion viscosity, Pa.s; rhoeIs the density of the microemulsion, kg/m3(ii) a K is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; ksRelative permeability of surfactant solution; keRelative permeability of microemulsion; ms-eThe fluidity ratio of the surfactant solution to the microemulsion is defined; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]。
Thereby completing the association of the surfactant solution displacement phase with the percolation rate forming microemulsion slug interfacial region under the gravitational effect.
And thirdly, by dividing four porous medium seepage areas from the injection end to the extraction end and constructing a critical interface, performing correlation of corresponding stable seepage velocity under the gravity effect on a second interface area along the way with a certain seepage inclination angle, namely an interface area of a microemulsion slug and a propelled oil wall, wherein the correlation expression is as follows:
however, since in the pushed "oil wall", both the oil phase and the water phase flow exist, that is, the fluidity of the "oil wall" region is composed of the oil phase fluidity and the water phase fluidity, the fluidity of the "oil wall" region is defined as:
in the above formula: ve-oThe seepage velocity of the microemulsion slug and the interface area forming an oil wall is m/s; rhoeIs the density of the microemulsion, kg/m3；ρoIs the density of the oil phase, kg/m3；μeIs microemulsion viscosity, Pa.s; mu.soIs the oil phase viscosity, Pa.s; mu.swIs the viscosity of the water phase, Pa.s; k is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; keRelative permeability of microemulsion; kroRelative permeability of the oil phase; krwRelative permeability of water phase; me-oThe fluidity ratio of the microemulsion to the oil wall; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]。
Thereby completing the relationship between the formation of microemulsion slugs under the effect of gravity and the speed of seepage that advances the "oil wall" interfacial region.
(IV) before the sand-packed physical model 1 changes the dip angle of the injection and production end, the injection pump 13 is started, and a certain known composition property and a displaced oil phase can be formed into a mixture 10-3The unitary surfactant system with ultra-low interface tension of mN/m is fed at a speed of 1m/dInjecting water into a surfactant solution container 12 to drive the sand-filled physical model 1 to residual oil saturation, opening a sampling valve 18 along the way to sample according to the interval of 0.15 times of pore volume injection amount along with the advance of a displacement front edge, taking a seepage medium with the maximum sampling viscosity as a microemulsion formed in unitary surfactant displacement, and synchronously sampling and testing the density of a microemulsion slug to obtain various physical parameters (rho) corresponding to known oil phase, water phase and surfactant solution at the front edgeo，μo，μw，ρs，μs，ρe，μe). Meanwhile, when the surfactant has ultralow interfacial activity, the relative permeability of the surfactant solution and the relative permeability of the microemulsion in the heterogeneous seepage process can be regarded as 1.
And determining the seepage velocity V of the surfactant solution displacement phase and the microemulsion slug forming interface region under the gravity effect when the dip angle of the injection and production end is changed to a certain seepage dip angle α according to the step (II) and the step (III)s-eAnd the seepage velocity V for forming a microemulsion slug and propelling an oil wall interface areae-o. Thus, the acquisition of the monoprotic surfactant flooding front and the seepage physical parameters of the physical model is completed.
Repeating the steps can obtain another physical property physical model, or the front edge of the surfactant system drive and the seepage property parameters of another composition property.
(V) the seepage velocity V of the two interface regions obtained for a certain seepage inclination angle αs-eAnd Ve-oAnd comparing, taking the smaller value of the two as the stable seepage speed for controlling the viscous fingering behavior to ensure that the stable multiphase seepage characteristic is maintained, and determining the critical injection flow of the surfactant solution for controlling the viscous fingering according to the following formula:
Q＝A·Vcrit
in the formula: q is the critical injection flow of the surfactant solution, m3S; a is the cross-sectional area perpendicular to the seepage direction, m2；VcritM-s。
According to the critical injection flow of the surfactant solution, an injection pump 13 is started, after the water-flooding residual oil saturation is established in a physical model, a unitary surfactant system with the same property as that in the step (IV) is utilized, a control valve 20 is switched, the constant flow displacement is carried out on the model with the injection and production seepage inclination angle α through a piston type surfactant solution container 12 to remove the oil-containing saturation, a back pressure pump 16, a pressure stabilizing tank 17 and a back pressure valve 19 are opened, a pressure sensor 15 and a collector 21 are started, and the improvement of the oil displacement efficiency is obtained by fully exerting the gravity effect to control the viscous finger advance behavior and stabilize the displacement front edge.
Sixthly, the injection-production seepage dip angle α (α E (0,90 DEG)) of the sand-pack physical model is changed and adjusted]) Sequentially determining V at corresponding inclination angless-eAnd Ve-oThe method comprises the following steps of dividing stable seepage speed limits when different injection and production seepage inclination angles are formed, further establishing a relation between an injection and production seepage inclination angle α and a critical injection flow Q of a surfactant solution according to the step (five), and further carrying out gravity effect stable displacement on a front edge to remove oil saturation according to the step (five) on the basis of the relation, so as to obtain oil displacement efficiency improvement values under a series of injection and production seepage inclination angles α, comparing the oil displacement efficiency improvement values, and taking α corresponding to the maximum improvement value as an injection and production seepage inclination angle optimization design value for controlling viscous fingering behavior of the surfactant system in the physical property by utilizing the gravity effect, thereby realizing quantitative association and description of exerting the gravity stability effect and controlling the viscous fingering behavior, and guiding the design and formulation of drilling oil displacement projects such as inclined wells, horizontal well deployment and the like in unitary surfactant oil production and the like.
Repeating the steps, changing the physical property of the injection-production seepage inclination angle adjustable sand-filling physical model or changing the composition property of a unitary surfactant system, dividing and establishing a quantitative relation between the injection-production seepage inclination angle α and the critical injection flow Q of the stable displacement front edge when oil reservoirs with different physical properties and different surfactant systems displace oil, and optimizing and determining the control capacity of the gravity effect on the viscous finger advancing behavior by measuring the corresponding oil-removing saturation effect.
The invention is a six-step method, aiming at the prominent viscous finger behavior of surfactant flooding oil when a fluidity control agent is absent, firstly creating a physical model for the reappearance and the differentiation of the gravity effect of fluid in the multi-phase seepage of a porous medium, secondly and thirdly dividing a seepage area in the advancing of a monophase surfactant flooding front edge, and effectively correlating the expression of the stable seepage velocity of the critical interface region, obtaining parameters for determining the stable seepage velocity of the monoprotic surfactant flooding gravity, constructing a method for controlling the viscous fingering behavior in the surfactant flooding oil by using the gravity effect, wherein the method is characterized in that the viscous fingering behavior in the monoprotic surfactant flooding oil is improved by using the excavation latent gravity auxiliary effect instead of the fluidity control agent, and the key for coping with the viscous fingering behavior is realized, and the sixth step is the optimization of the viscous fingering behavior control capability of the gravity effect, so that the viscous fingering and the optimization of the viscous fingering behavior in the surfactant flooding oil are realized by using the gravity effect.
The tests of the microemulsion density, the surfactant solution density and the oil phase density all adopt a U-shaped tube oscillation method. The microemulsion viscosity, the surfactant solution viscosity, the oil phase viscosity and the water phase viscosity are tested by a rotation method. The monobasic surfactant solution displacement phase forms with the displaced oil phase 10-3An ultra-low interfacial tension of mN/m. The sampling interval in the displacement front and acquisition of the percolation property parameters was 0.15 times the pore volume injection.
The invention well deals with the problem that when a unitary surfactant is used for oil displacement, because a fluidity control agent represented by a conventional polymer is lost, the viscosity of the aqueous solution of the unitary surfactant is very low, and a prominent viscous fingering behavior appears in a heterogeneous oil reservoir, so that the propulsion of a displacement front edge is unstable, and the effect of removing the oil saturation of the displacement front edge is directly influenced. The method has the advantages that multiphase seepage characteristics of different areas of the porous medium under the influence of the phase behavior of the surfactant solution are considered, a stable seepage technical limit for controlling the viscosity fingering behavior in the whole injection and production process by the gravity effect is established, an optimization method for controlling the viscosity fingering by the gravity auxiliary effect is formed, the improvement of multiphase seepage characteristics of the monobasic surfactant flooding can be met when the fluidity control agent is replaced by the gravity effect, and the stable flooding front edge and oil saturation removal effects are obtained. The method is scientific, clear in principle, clear in process, reasonable in device structure, standard in technical parameters, simple and easy to operate, convenient for breaking through the limitation of the traditional polymer mobility control agent, guiding the optimal design and effective butt joint of the inclined shaft development technology, and popularizing and applying the monobasic surfactant flooding in the high water cut period oilfield dead-end residual oil excavation and submergence.
Claims (10)
1. A gravity effect control surface active agent drives oil in the viscidity to point and optimizes the method, characterized by that:
designing a pouring-mining seepage inclination angle adjustable sand-packed physical model: establishing an original bound water state of a sand-filled physical model (1) compacted according to the hole and seepage parameter requirements and the selection of quartz sand mesh and mixing proportion, driving water to residual oil saturation, obtaining the relative permeability of water phase and the relative permeability of oil phase of the sand-filled physical model (1), completing the construction of the sand-filled physical model (1) of residual oil saturation, then placing the sand-filled physical model (1) on a turning shaft (4) through a slip joint (8), connecting one end of the turning shaft (4) with a rotary bearing seat (2) and the other end with a single-head turbine worm speed reducer (3), installing the rotary bearing seat (2) on a support frame (7), connecting an angular displacement transmitter (6) with the single-head turbine worm speed reducer (3) through an input flange bolt, and driving the single-head turbine worm (3) to obtain power output by utilizing a coded disc motor (5) with high precision, the sand-packed physical model (1) is obliquely arranged, the injection end of the sand-packed physical model (1) is arranged at the lower part, the sand-packed physical model (1) type extraction end is arranged at the upper part, the sand-packed physical model (1) is rotated to different degrees, the change of the inclination angles of the two ends of the sand-packed physical model (1) is realized, the injection-production seepage inclination angle is measured and controlled by an angular displacement transmitter (6) connected to a single-head worm gear reducer (3), and the self-locking of the target adjustment inclination angle is realized by the single-head worm gear reducer (3); meanwhile, in order to obtain physical parameters of fluid in the migration of the displacement front edge, a sand-packed physical model (1) arranges sampling points along the way from the injection end to the extraction end; completing the design of the injection-production seepage inclination angle adjustable sand-packed physical model;
(II) correlating the surfactant solution displacement phase with the seepage velocity of the microemulsion slug interface region forming by gravity effect: considering that a microemulsion slug is inevitably formed by the emulsification of a surfactant system and residual oil while the adhesion work is reduced and the residual oil is peeled off to form an oil wall propulsion in the monobasic surfactant oil flooding process, dividing a porous medium region of a sand-filled physical model (1) into a surfactant solution displacement phase region, a microemulsion slug region, an oil wall region and a residual oil zone region from an injection end to a production end of the sand-filled physical model (1) in the multiphase seepage front propulsion, and constructing a critical interface for controlling the viscous advancing behavior; for the in-path first interface region: the stable seepage velocity expression of the interface region of the surfactant solution displacement phase and the microemulsion slug forming phase in the presence of the associated gravitational effect according to Darcy's law when the interface region has a certain seepage inclination angle:
wherein,
in the above formula: vs-eThe seepage velocity m/s is the seepage velocity of a surfactant solution displacement phase and a formed microemulsion slug interface area; rhosAs the density of the surfactant solution, kg/m3；μsIs the surfactant solution viscosity, Pa.s; mu.seIs microemulsion viscosity, Pa.s; rhoeIs the density of the microemulsion, kg/m3(ii) a K is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; ksRelative permeability of surfactant solution; keRelative permeability of microemulsion; ms-eThe fluidity ratio of the surfactant solution to the microemulsion is defined; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]；
(III) the formation of a microemulsion slug under the effect of gravity is associated with the seepage velocity of the propelling 'oil wall' interface region: second interface region along path with a certain seepage inclination: the micro-emulsion slug and the interface area of the propelled oil wall are associated with the corresponding stable seepage velocity under the gravity effect, and the associated expression is as follows:
however, in the advanced "oil wall", both a mobile oil phase and a mobile water phase exist, and the fluidity of the "oil wall" region is composed of the oil phase fluidity and the water phase fluidity, so that the definition:
in the above formula: ve-oThe seepage velocity of the microemulsion slug and the interface area forming an oil wall is m/s; rhoeIs the density of the microemulsion, kg/m3；ρoIs the density of the oil phase, kg/m3；μeIs microemulsion viscosity, Pa.s; mu.soIs the oil phase viscosity, Pa.s;μwis the viscosity of the water phase, Pa.s; k is the absolute permeability of the model, m2(ii) a Phi is the model porosity,%; keRelative permeability of microemulsion; kroRelative permeability of the oil phase; krwRelative permeability of water phase; me-oThe fluidity ratio of the microemulsion to the oil wall; g is a gravitational acceleration constant of 9.8m/s2α is the injection-production seepage inclination angle, α e (0,90 degree)]；
(IV) acquiring a monophyletic surfactant flooding front edge and seepage physical property parameters of the physical model: before the sand-packed physical model (1) changes the dip angle of the injection and production end, a unitary surfactant system with known composition properties is injected into the sand-packed physical model (1) of water drive to residual oil saturation, sampling is sequentially carried out along the way sampling points along with the advance of the displacement front edge, a seepage medium with the maximum sampling viscosity is used as a microemulsion formed in the unitary surfactant displacement, the density of a microemulsion slug is synchronously sampled and tested, and physical parameters corresponding to the known oil phase, the known water phase and the known surfactant solution at the front edge are obtained, wherein the physical parameters comprise rhoo，μo，μw，ρs，μs，ρe，μe(ii) a Meanwhile, when the surfactant has ultralow interfacial activity, the relative permeability of the surfactant solution and the relative permeability of the microemulsion in the multi-phase seepage process can be regarded as 1;
and determining the seepage velocity V of the surfactant solution displacement phase and the formed microemulsion slug interface region under the gravity effect when the dip angle of the injection and production end is changed to a certain seepage dip angle α according to the step (II) and the step (III)s-eAnd the seepage velocity V for forming a microemulsion slug and propelling an oil wall interface areae-o；
Completing the acquisition of the displacement front edge and the seepage physical property parameters;
(V) stabilizing the oil saturation degree of the displacement front edge by gravity effect, namely ensuring that the stable multiphase seepage characteristic is maintained, and obtaining the seepage velocity V of the first interface region and the second interface region along the way when a certain seepage inclination angle α is mets-eAnd Ve-oComparing, taking the smaller value of the two as the stable seepage speed for controlling the viscous finger behavior, and determining the control viscosity according to the following formulaCritical injection flow rate of surfactant solution by sexually advancing:
Q＝A·Vcrit
in the formula: q is the critical injection flow of the surfactant solution, m3S; a is the cross-sectional area perpendicular to the seepage direction, m2；VcritM/s for stable seepage velocity;
according to the critical injection flow of the surfactant solution, after the water flooding residual oil saturation is established in a physical model, a unitary surfactant system with the same property as that in the step (IV) is used for performing constant flow displacement on the model with the injection and production seepage inclination angle α to remove the oil saturation, and the improvement of the oil displacement efficiency is obtained by fully exerting the gravity effect to control the viscous fingering behavior and stabilizing the displacement front edge;
thus, the method construction for controlling the viscosity fingering behavior in the surfactant flooding by the gravity effect is completed;
(VI) stable seepage technical limit division and viscosity fingering control capability optimization of variable injection-production seepage inclination angle, namely changing and adjusting injection-production seepage inclination angle α (α epsilon (0,90 DEG degree) of sand-packed physical model (1)]) Sequentially determining V at corresponding inclination angless-eAnd Ve-oDividing stable seepage velocity limits when different injection and production seepage dip angles are formed, further establishing a relation between an injection and production seepage dip angle α and a critical injection flow Q of a surfactant solution according to the step (five), and further carrying out gravity effect stable displacement of a front edge to remove oil saturation according to the step (five) on the basis of the relation to obtain oil displacement efficiency improvement values under a series of injection and production seepage dip angles α;
therefore, the stable seepage technical limit division of the variable injection-production seepage inclination angle and the optimization of the control method of the viscous finger are completed.
2. The gravity effect control surfactant flooding viscosity fingering optimization method according to claim 1 is characterized in that the steps (I) to (VI) are repeated, physical properties of the sand-packed physical model (1) are changed, or composition properties of a unitary surfactant system are changed, a quantitative relation between an injection and production seepage dip angle α and a stable flooding front critical injection flow rate Q is established in a dividing mode when oil reservoirs with different physical properties and different surfactant systems are displaced, and the control capacity of the gravity effect on the viscosity fingering behavior is optimized and determined by measuring corresponding oil-removing saturation effects.
3. The gravity effect controlled viscosity index optimization method in surfactant flooding of claim 2, wherein: the angular displacement transmitter (6) controls the adjustment range of the injection-production seepage inclination angle to be 0-90 degrees, and the adjustment precision is 1 degree.
4. The gravity effect controlled viscosity index optimization method in surfactant flooding of claim 3, wherein: and (3) acquiring the water phase relative permeability and the oil phase relative permeability of the physical filling sand model in the step (III) by adopting an unsteady state method.
5. The gravity effect controlled viscosity index optimization method in surfactant flooding of claim 4, wherein: and (IV) when the displacement front and the seepage physical parameters are obtained, the injection speed of the univalent surfactant is 1 m/d.
6. An apparatus for use in a gravity effect controlled viscosity index optimization method for surfactant flooding as claimed in claim 5, wherein: the device used by the gravity effect control surfactant flooding viscosity finger-entering optimization method comprises an adjustable sand-filling physical model, a piston type oil container (10), a piston type salt water container (11), a piston type surfactant solution container (12), an injection pump (13), a constant temperature system (14), a pressure sensor (15), a collector (21) and an automatic control system (22), wherein the adjustable sand-filling physical model, the piston type oil container (10), the piston type salt water container (11) and the piston type surfactant solution container (12) are all arranged in the constant temperature system (14); the adjustable sand-filling physical model comprises a sand-filling physical model (1), a support frame (7), a turning shaft (4), a single-head turbine worm speed reducer (3) and an angular displacement transmitter (6), wherein the sand-filling physical model (1) is arranged on the turning shaft (4) through a slip joint (8), one end of the turning shaft (4) is connected with a rotary bearing seat (2), the other end of the turning shaft is connected with the single-head turbine worm speed reducer (3), the rotary bearing seat (2) is arranged on the support frame (7), a servo motor (5) with a high-precision code disc is used for driving the single-head turbine worm speed reducer (3) to obtain power output, the angular displacement transmitter (6) is connected to the single-head turbine worm speed reducer (3) through an input flange bolt, the sand-filling physical model (1) is obliquely arranged, the injection end of the sand-filling physical model (1) is arranged below, a sampling valve (18) is arranged on the sand-packed physical model (1) from the injection end to the extraction end along the way, and control valves (20) are arranged at the front and the back of the sand-packed physical model (1);
the piston type oil container (10), the piston type saline water container (11) and the piston type surfactant solution container (12) are connected in parallel to form a container group, an injection pump (13) is connected with the input end of the container group, the output end of the container group is connected with the sand-filled physical model (1), the output end of the container group is also provided with a pressure sensor (15), and the extraction end of the sand-filled physical model (1) is connected with the collector (21) through a silica gel hose;
the single-head worm gear speed reducer (3), the servo motor (5), the angular displacement transmitter (6), the injection pump (13), the constant temperature system (14), the pressure sensor (15), the sampling valve (18), the control valve (20) and the collector (21) are connected with the automatic control system (22).
7. The apparatus for use in a gravity effect controlled viscosity index optimization process in surfactant flooding of claim 6, wherein: the front end of the collector (21) is provided with a back pressure control unit which is jointly composed of a back pressure pump (16), a pressure stabilizing tank (17) and a back pressure valve (19), and the back pressure valve (19) and the back pressure pump (16) are connected with an automatic control system (22).
8. The apparatus for use in a gravity effect controlled viscosity index optimization process in surfactant flooding of claim 7, wherein: the sand-packed physical model (1) is made of stainless steel, the diameter of the sand-packed physical model is 50mm, the length of the sand-packed physical model is 500mm, and 3 sampling valves (18) are equidistantly arranged from the injection end to the extraction end of the sand-packed physical model.
9. The apparatus for use in a gravity effect controlled viscosity index optimization process in surfactant flooding of claim 8, wherein: the reduction ratio of the single-head worm and gear speed reducer (3) is 1:10, and the maximum displacement recognition rate of the servo motor (5) adopting a high-precision code disc is less than 0.02 degrees.
10. The apparatus for use in a gravity effect controlled viscosity fingering optimization process in surfactant flooding of claim 9, wherein: the overturning shaft (4) is connected with the sand-packed physical model (1) through a slip joint (8) in the centers of the overturning shaft and the sand-packed physical model; a triangular welding platform (9) is arranged on the side surface of the support frame (7), and an angle of 45 degrees is formed between the triangular welding platform (9) and the horizontal plane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810485011.1A CN108716392B (en) | 2018-05-20 | 2018-05-20 | Gravitational effect controls viscous fingering optimization method and device in surfactant flooding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810485011.1A CN108716392B (en) | 2018-05-20 | 2018-05-20 | Gravitational effect controls viscous fingering optimization method and device in surfactant flooding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108716392A true CN108716392A (en) | 2018-10-30 |
| CN108716392B CN108716392B (en) | 2019-03-22 |
Family
ID=63900086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810485011.1A Active CN108716392B (en) | 2018-05-20 | 2018-05-20 | Gravitational effect controls viscous fingering optimization method and device in surfactant flooding |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108716392B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113622883A (en) * | 2021-09-16 | 2021-11-09 | 西南石油大学 | Gravity-assisted flooding simulation experiment device and method for gas-assisted viscosity reducer at different inclination angles |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110017455A1 (en) * | 2009-07-22 | 2011-01-27 | Conocophillips Company | Hydrocarbon recovery method |
| CN102654046A (en) * | 2012-05-10 | 2012-09-05 | 中国石油天然气股份有限公司 | Top air injection gravity assisted flooding oil extraction two-dimensional physical simulation experiment system |
| CN105114062A (en) * | 2015-09-21 | 2015-12-02 | 山东科技大学 | Testing device for simulating permeability rule of low-permeability horizontal well and testing method |
| CN106121603A (en) * | 2016-06-25 | 2016-11-16 | 东北石油大学 | A kind of device simulating different angle oil reservoir oil displacement efficiency and method |
-
2018
- 2018-05-20 CN CN201810485011.1A patent/CN108716392B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110017455A1 (en) * | 2009-07-22 | 2011-01-27 | Conocophillips Company | Hydrocarbon recovery method |
| CN102654046A (en) * | 2012-05-10 | 2012-09-05 | 中国石油天然气股份有限公司 | Top air injection gravity assisted flooding oil extraction two-dimensional physical simulation experiment system |
| CN105114062A (en) * | 2015-09-21 | 2015-12-02 | 山东科技大学 | Testing device for simulating permeability rule of low-permeability horizontal well and testing method |
| CN106121603A (en) * | 2016-06-25 | 2016-11-16 | 东北石油大学 | A kind of device simulating different angle oil reservoir oil displacement efficiency and method |
Non-Patent Citations (1)
| Title |
|---|
| 钟会影: ""粘弹性聚合物驱普通稠油微观渗流数学模型"", 《地球科学》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113622883A (en) * | 2021-09-16 | 2021-11-09 | 西南石油大学 | Gravity-assisted flooding simulation experiment device and method for gas-assisted viscosity reducer at different inclination angles |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108716392B (en) | 2019-03-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108131122B (en) | Method for improving CO2 sequestration and crude oil recovery | |
| CN110318721B (en) | Method for improving recovery ratio by foam flooding auxiliary nitrogen huff and puff of fault block oil reservoir | |
| CN105626006A (en) | CO2 drive technological limit well spacing determination method for low-permeability oil reservoir | |
| CN110778272B (en) | Non-excavation laying construction method for large-diameter heat supply network pipeline | |
| CN108533239B (en) | Utilize viscous fingering method and device in gravitational effect control surfactant flooding | |
| CN104929115A (en) | Single-shaft cemented soil stirring pile machine capable of working in lower clearance mode and construction method of single-shaft cemented soil stirring pile machine | |
| CN105804761A (en) | Construction method suitable for making shield penetrate through building in close range on liquefied sandy soil stratum | |
| CN107842374B (en) | The novel inert slurry of shield and combination grouting process for upper soft lower hard water rich strata | |
| CN110145230A (en) | A kind of horizontal directional drilling trombone slide method | |
| CN109594990A (en) | A kind of bad ground big cross section pipe jacking construction method | |
| CN104533362A (en) | Method for increasing volume expansion of CO2 and crude oil system liquid phase in non-miscible-phase displacement | |
| CN108716392B (en) | Gravitational effect controls viscous fingering optimization method and device in surfactant flooding | |
| CN110318718A (en) | A kind of low-permeability oil deposit CO2Mixed phase drives critical spacing calculation method | |
| Sun et al. | Insights into enhanced oil recovery by thermochemical fluid flooding for ultra-heavy reservoirs: An experimental study | |
| CN103122756B (en) | Method for confirming deepwater water separating pipe gas lift drilling well gas injection volume | |
| CN112943230B (en) | Residual oil distribution prediction method for common heavy oil reservoir | |
| CN109611098A (en) | A kind of shaft of vertical well quick freezing method under the conditions of deep layer runoff water is larger | |
| CN107761717A (en) | The construction method of sand content in mud is controlled in filling pile construction | |
| CN105158036A (en) | Preparation method of rock sample simulating oil and water differential distribution | |
| CN104963675A (en) | Method for forecasting temporary plugging acidization acid liquor advancing distance of horizontal well | |
| CN104879106A (en) | Method for raising recovery efficiency of heavy oil deposit through chemical steam flooding | |
| CN113759099B (en) | Quantitative evaluation method for oil-gas filling capacity of source-storage side-connected oil-gas reservoir | |
| CN204984265U (en) | Particle filling pipe system | |
| CN104989344A (en) | Method for determining gas channeling degree in nitrogen foam oil displacing process | |
| CN214287034U (en) | Petroleum filtering device for offshore oil exploitation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |