CN113982568B - Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking - Google Patents
Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking Download PDFInfo
- Publication number
- CN113982568B CN113982568B CN202111401787.9A CN202111401787A CN113982568B CN 113982568 B CN113982568 B CN 113982568B CN 202111401787 A CN202111401787 A CN 202111401787A CN 113982568 B CN113982568 B CN 113982568B
- Authority
- CN
- China
- Prior art keywords
- cluster
- cracking
- pressure
- fracture
- perforation
- 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.)
- Active
Links
- 238000005336 cracking Methods 0.000 title claims abstract description 146
- 238000000034 method Methods 0.000 title claims abstract description 55
- 230000000977 initiatory effect Effects 0.000 claims abstract description 35
- 239000012530 fluid Substances 0.000 claims description 44
- 238000009826 distribution Methods 0.000 claims description 43
- 238000010276 construction Methods 0.000 claims description 26
- 230000002860 competitive effect Effects 0.000 claims description 20
- 238000002347 injection Methods 0.000 claims description 19
- 239000007924 injection Substances 0.000 claims description 19
- 238000006073 displacement reaction Methods 0.000 claims description 15
- 239000004215 Carbon black (E152) Substances 0.000 claims description 10
- 229930195733 hydrocarbon Natural products 0.000 claims description 10
- 150000002430 hydrocarbons Chemical class 0.000 claims description 10
- 230000008878 coupling Effects 0.000 claims description 9
- 238000010168 coupling process Methods 0.000 claims description 9
- 238000005859 coupling reaction Methods 0.000 claims description 9
- 238000003860 storage Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 238000004590 computer program Methods 0.000 claims description 4
- 230000000704 physical effect Effects 0.000 claims description 3
- 239000011148 porous material Substances 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 20
- 230000008859 change Effects 0.000 abstract description 12
- 230000004048 modification Effects 0.000 abstract description 5
- 238000012986 modification Methods 0.000 abstract description 5
- 238000005457 optimization Methods 0.000 abstract description 4
- 238000005086 pumping Methods 0.000 abstract description 2
- 238000004364 calculation method Methods 0.000 description 8
- 238000011065 in-situ storage Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 238000004891 communication Methods 0.000 description 5
- 239000011435 rock Substances 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 235000021185 dessert Nutrition 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012821 model calculation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012795 verification Methods 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
- E21B47/00—Survey of boreholes or wells
- E21B47/06—Measuring temperature or pressure
-
- 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
- E21B43/11—Perforators; Permeators
-
- 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
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
-
- 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
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
-
- 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
- E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
- E21B2200/20—Computer models or simulations, e.g. for reservoirs under production, drill bits
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/40—Controlling or monitoring, e.g. of flood or hurricane; Forecasting, e.g. risk assessment or mapping
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)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a method for predicting the bottom hole pressure of multi-crack competition and initiation of compact oil and gas, which utilizes crack extension pressure and hole friction to realize real-time control on the crack initiation and extension sequence, and realizes the multi-cluster jet hole competition and initiation and extension of a compact sandstone horizontal well, thereby simulating the change process of the bottom hole pressure of multi-crack competition and initiation, and more accurately predicting the bottom hole pressure of multi-crack competition and initiation of compact oil and gas according to the change process. By adopting the dense oil gas multi-crack competition cracking bottom hole pressure prediction method, the size and the change rule of bottom hole pressure in the fracturing pumping process can be accurately predicted, so that reliable guiding basis is provided for the efficient modification parameter optimization of dense sandstone.
Description
Technical Field
The invention relates to compact oil gas development, in particular to a method for predicting bottom hole pressure of multiple cracks of compact oil gas in competition.
Background
The tight sandstone horizontal well adopts a staged multi-cluster fracturing mode to fully utilize the reservoir, but not all perforation clusters can be simultaneously cracked due to the influence of ground stress and reservoir heterogeneity, and the cracking perforation clusters firstly enter an extension stage to generate induced stress, so that the in-situ stress of the stratum can be influenced, and the newly calculated cracking pressure of the follow-up uncracked perforation clusters is influenced.
Disclosure of Invention
The first aspect of the present invention aims to provide a method for realizing real-time control of crack initiation and extension sequences by using crack extension pressure and hole friction, so as to realize multi-cluster injection hole competitive initiation and extension of a tight sandstone horizontal well, thereby simulating a multi-crack competitive initiation bottom hole pressure change process, and according to the change process, more accurately predicting the multi-crack competitive initiation bottom hole pressure of the tight oil gas, the second aspect of the present invention aims to provide an electronic device capable of executing the method of the first aspect, and the third aspect of the present invention aims to provide a computer readable storage medium storing executable instructions capable of executing the method of the first aspect.
The technical scheme adopted by the invention is that the method for predicting the bottom hole pressure of the compact oil gas multi-crack competition cracking comprises the following steps:
s1, acquiring initial flow distribution data and acquiring the cracking sequence of each cluster;
S2, giving a time step of extending a subsequent crack according to the crack starting sequence of each cluster;
S3, in the time step, when the time step is set at the first moment, assuming a flow distribution value, judging whether a crack extends or not;
s3.1, if the flow distribution is not extended, changing the flow distribution;
S3.2, if the well bottom pressure generated by the first cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster are obtained, and whether the well bottom pressure generated by the first cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion is judged;
S4, after the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion, acquiring the half-joint length and the net pressure of the cracking perforation cluster, the induced stress and the new cracking pressure of the non-cracking perforation cluster at different moments according to the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster;
S5, when the bottom hole pressure calculated according to the half-seam length, the net pressure and the generated induced stress of the pre-cracking perforation cluster is larger than the new cracking pressure of any one of the non-cracking perforation clusters, the judgment that the perforation cluster is cracked and enters an extension stage can be obtained;
s6, calculating construction time, and judging whether the given construction time is reached;
S6.1, if the given construction time is reached, completing the whole prediction step;
And S6.2, if the given construction time is not reached, returning to the step S3 until the construction time is over.
By adopting the dense oil gas multi-crack competition cracking bottom hole pressure prediction method, the size and the change rule of bottom hole pressure in the fracturing pumping process can be accurately predicted, so that reliable guiding basis is provided for the efficient modification parameter optimization of dense sandstone.
Further, the determining whether the bottom hole pressure generated by the pre-cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion comprises:
If the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion, increasing the time step and performing step S4;
if the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster do not meet the pressure flow balance criterion, changing the flow distribution until the conditions are met, and then performing step S4.
Further, before the prediction method of the tight oil gas multi-crack competition cracking bottom hole pressure is used for prediction, a multi-cluster crack flow dynamic distribution model, a perforation cluster crack extension model and a hydraulic crack induced stress model are constructed based on a tight sandstone horizontal well seepage-stress cracking pressure prediction model;
According to the multi-cluster crack flow dynamic distribution model, the perforation cluster crack extension model and the hydraulic crack induced stress model, a shale horizontal well multi-cluster perforation competition cracking and extension model is constructed, and initial flow distribution data and the cracking order of each cluster are obtained according to the shale horizontal well multi-cluster perforation competition cracking and extension model.
Further, the constructing a multi-cluster fracture flow dynamic distribution model, a perforation cluster fracture extension model and a hydraulic fracture induced stress model comprises the following steps:
establishing a horizontal well sectional multi-cluster flow dynamic distribution model according to the friction of the shaft and the perforation, and obtaining flow dynamic distribution data by the horizontal well sectional multi-cluster flow dynamic distribution model;
constructing a fracture extension model and a fracture induced stress model of a fracture-initiating perforation cluster according to the heterogeneous reservoir physical properties and the ground stress difference;
and (3) coupling single-cluster fracture initiation data, flow dynamic allocation data, a fracture initiation perforation cluster fracture extension model and a fracture induced stress model, and constructing a shale horizontal well multi-cluster perforation competition initiation and extension model.
Further, the constructing the multi-cluster fracture flow dynamic distribution model comprises coupling the inlet flow of each cluster of fractures and the total pressure of the root end of the horizontal well.
Further, the multi-cluster crack flow dynamic distribution model is as follows:
The total displacement of the Q-fracturing fluid injection, m 3/min;
Q i -the flow of the ith crack, m 3/min;
m-total cluster number in the same fracturing section, and dimensionless;
p 0 -fluid pressure at heel end of horizontal well, MPa;
pressure loss of the p cf,i -ith fracture along the wellbore, MPa;
Fluid pressure at the inlet of the p w,i -ith crack is MPa;
p pf,i -ith crack perforation friction resistance, MPa;
d p,i -ith crack perforation hole diameter, m;
c d,i -ith crack aperture flow coefficient, dimensionless;
ρ s —density of fracturing fluid, kg/m 3;
n p,i -the number of holes of the ith crack, and has no dimension.
Further, the perforation cluster crack extension model is:
pfr1＞pfr3＞pw＞pfr2
p w -bottom hole pressure, MPa;
p fr1 -newly calculated cracking pressure of the first cluster, MPa;
p fr2 -newly calculated cracking pressure of the second cluster, MPa;
p fr3 -newly calculated cracking pressure of the third cluster, MPa;
pfr1＞pfr3＞pw＝σh+pnet,2+ppf,2
p net,2 -the second cluster generates net fluid pressure in the fracture, MPa;
p pf,2 -the pore friction of the second cluster, MPa.
Q 2 -displacement of the second cluster, m 3/min;
c-comprehensive fluid loss coefficient, m/min 1/2;
H f -hydraulic fracture height, m;
t-liquid injection time, min;
E-Young's modulus;
mu-poisson ratio, dimensionless;
V-poisson ratio, dimensionless;
L f,2 -hydraulic fracture length, m;
w f,2 -the seam width of the hydraulic fracture, m;
I.e. in the above case, when the bottom hole pressure is greater than the newly calculated cracking pressure of the second cluster, i.e. p fr1＞pfr3＞pw > p as described above;
as the construction proceeds, when the bottom hole pressure is further greater than the newly calculated cracking pressure of the third cluster, the third cluster cracks, i.e.: p fr1＞pw＞pfr3
And calculating the new cracking pressure and the bottom hole pressure of the first cluster in real time on the basis of the new in-situ stress, and when the bottom hole pressure is larger than the newly calculated cracking pressure of the first cluster, the first cluster cracks and extends, so as to finally realize the competition cracking and expansion of the multi-cluster jet holes.
The second aspect of the invention also provides an electronic device comprising a processor and a memory; the memory is used for storing processor executable instructions; the processor is configured to perform the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method of the first aspect.
By adopting the electronic device, the magnitude and the change rule of the bottom hole pressure in the fracturing pump injection process can be accurately predicted, so that the high-efficiency modification parameters of the tight sandstone can be better optimized.
A third aspect of the invention also provides a computer readable storage medium comprising a stored computer program which, when run, performs the tight hydrocarbon multi-fracture competitive initiation bottom hole pressure prediction method of the first aspect.
Drawings
The accompanying drawings, which are included to provide a further understanding of embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:
FIG. 1 is a schematic diagram of a multi-cluster fracture flow dynamic allocation physical model in an embodiment;
FIG. 2 is a schematic illustration of an in-segment multi-shower hole in an embodiment;
FIG. 3 is a vertical fracture physical model in an embodiment;
FIG. 4 is a schematic diagram of a two-dimensional vertical fracture in an embodiment;
FIG. 5 is a schematic diagram of fracture diversion in an embodiment
FIG. 6 is a flow chart of a dense gas horizontal well multi-shower hole competitive fracturing and expansion model procedure in an embodiment;
FIG. 7 is a graph of bottom hole pressure versus time for a newly calculated fracture initiation pressure in an embodiment;
FIG. 8 is a graph of bottom hole pressure versus time for a newly calculated cracking pressure 15s in an embodiment;
Detailed Description
For the purpose of making apparent the objects, technical solutions and advantages of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present invention and the descriptions thereof are for illustrating the present invention only and are not to be construed as limiting the present invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: no such specific details are necessary to practice the invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail in order not to obscure the invention.
Throughout the specification, references to "one embodiment," "an embodiment," "one example," or "an example" mean: a particular feature, structure, or characteristic described in connection with the embodiment or example is included within at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment," "in an example," or "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Moreover, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and that the illustrations are not necessarily drawn to scale. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the scope of the present invention.
Because the horizontal well multi-cluster perforation competition cracking and expanding are a very complex physical process, the horizontal well multi-cluster perforation competition cracking and expanding are mutually interfered by a plurality of influencing factors, and the following processes are mainly coupled: ① Single cluster fracture initiation; ② Dynamically distributing the flow of the multi-cluster cracks; ③ Firstly, cracking perforation clusters are extended; ④ The perforation cluster is first cracked and extended to generate induced stress. The method comprises the steps of establishing a corresponding competitive cracking and expanding model by considering single-cluster cracking, flow dynamic distribution, cracking perforation cluster extension and induced stress generated by cracking perforation cluster extension, and revealing a sandstone multi-crack competitive cracking and expanding mechanism, so that theoretical guidance is provided for sandstone efficient transformation parameter optimization. The compact sandstone horizontal well multi-cluster injection hole competes for cracking and expands a physical model, builds the physical model and develops further researches, and makes the following basic assumptions:
(1) The compressive stress is positive and the tensile stress is negative;
(2) The fracture section is a homogeneous and isotropic elastomer, and the fracture section is an elliptical fracture;
(3) The chemical action of the fracturing fluid after the action of the fracturing fluid and the reservoir rock is not considered;
(4) Only one crack is generated in one cluster;
(5) The hydraulic fracturing forms any angle crack, and the included angle between the crack and the minimum horizontal main stress is alpha, and alpha is more than or equal to 0 and less than or equal to 90 degrees.
According to the method for predicting the bottom hole pressure of the dense oil gas multi-crack competition cracking, a multi-cluster crack flow dynamic distribution model is established.
After a tight sandstone horizontal well seepage-stress cracking pressure prediction model is established, combining the actual field sectional multi-cluster perforation fracturing, and further expanding the tight sandstone horizontal well seepage-stress cracking pressure prediction model to the horizontal well sectional multi-cluster perforation competition cracking and expansion simulation; the horizontal well multi-cluster perforation competition cracking and expansion are needed to solve the problem of multi-crack flow dynamic distribution. The embodiment takes into account the dynamic coupling of the bottom hole pressure and the flow to establish a flow dynamic distribution model.
The seepage-stress cracking pressure prediction model of the tight sandstone horizontal well is as follows:
Wherein:
-normal principal stress components of each face in the coordinate system (x, y, z), MPa;
-shear stress components of each facet in the coordinate system (x, y, z), MPa.
Sigma H、σh、σv -maximum and minimum horizontal principal stress and vertical stress, MPa;
Psi, beta-well inclination angle and azimuth angle, °
Sigma R、σθ、σz -radial stress, circumferential stress and axial stress component along the wellbore direction, MPa;
Tau Rθ、τθz、τRz -shear stress, MPa
R w, R-wellbore radius and radial distance from a point in the formation to the wellbore center, m;
p w -bottom hole pressure, MPa;
V-poisson ratio of the formation and casing, dimensionless;
TF-conductivity, which represents the conduction of pressure in the wellbore into the formation rock.
Θ -azimuth angle of perforation, °.
-Radial stress, circumferential stress and axial stress along the wellbore direction, MPa, respectively;
Shear stress around the wellbore, MPa.
The embodiment establishes the multi-cluster fracture flow dynamic distribution model, firstly determines a flow conservation criterion, and the physical model of the multi-cluster perforation competition cracking and expansion flow dynamic distribution of the compact sandstone horizontal well is shown in fig. 1, wherein the schematic diagram shows the situation that a certain section is divided into multiple clusters. Based on Kirchoff's first law, when carrying out horizontal well segmentation multi-cluster fracturing, the total injection displacement of fracturing fluid is Q, and total flow is divided into each cluster, and the displacement of every cluster is Q i, and the total displacement of fluid equals the sum of every cluster displacement of all cracks, namely:
wherein the total displacement of Q-fracturing fluid injection, m 3/min;
m-total cluster number in the same fracturing stage, and no dimension.
E z、er in fig. 1-wellbore direction, fracture propagation direction; fluid pressure at the inlet of the p w,i -ith crack is MPa; p pf,i -ith crack perforation friction resistance, MPa.
Then, establishing a pressure balance criterion, wherein the embodiment establishes the fluid pressure balance criterion in the well bore by taking the root end (A target point) of the horizontal well as a reference point based on the Kirchoff second law. The pressure at the root end of the horizontal well is equal to the sum of the fluid pressure at the entry of each cluster of fractures, the friction at the perforation and the pressure loss of the fracturing fluid along the wellbore. When a segment is divided into m clusters, there are m pressure balance equations:
p0＝pw,i+ppf,i+pcf,i(i＝1,2,…,m) (0-2)
wherein p 0 is the pressure of fluid at the heel end of the horizontal well and MPa;
pressure loss along the well bore of the p cf,i -ith fracture, MPa.
The fluid pressure p w,i at the entry of the ith fracture is an unknown quantity, and the calculation method will be described in detail later. The friction of the perforation holes can influence the pressure distribution of fracturing fluid in the fracturing construction, so that the flow distribution in the multi-cluster fracture initiation process is seriously influenced, the initiation pressure is finally influenced, and the hydraulic fracturing system is an important parameter in the hydraulic fracturing implementation process. Based on Bernoulli equation, the calculation formula of the multi-fracture perforation friction is as follows:
Wherein d p,i is the diameter of the perforation hole of the ith crack, m;
c d,i -ith fracture perforation flow coefficient, dimensionless.
In the early stage of fracturing, the pad fluid does not erode the shot Kong Kongyan, so that the effect on the orifice flow coefficient C d,i is small, and generally 0.56 is taken. The pressure loss along the well bore is proportional to the crack spacing, and the pressure loss of each crack on the horizontal well bore is calculated by the following formula:
Wherein C cf -friction coefficient, pa.s/m 4;
x j -distance from crack j to heel end of shaft, m;
q w,j -the volume flow remaining after passing through j cracks, m 3/min;
d-diameter of horizontal well shaft, m.
And finally, coupling the pressure and the flow.
When fracturing fluid enters each cluster, the fluid pressure p w,i at the inlet of each crack and the original stratum pressure p p induce an outer radial flow in the permeated rock, and the seepage rule of the outer radial flow follows one-dimensional Darcy radial seepage. The fracture entry, i.e., perforation, then the fluid pressure p w,i at each fracture entry is equal to perforation pressure p w.
Obtained by combining formula (0-1) and formula (0-2):
The unknowns in the equation set formed by the above formulas (0-5) are the inlet flow rate Q i of each cluster crack and the total pressure p 0 of the root end of the horizontal well, and m+1 equations and m+1 unknowns are in total.
And constructing a perforation cluster crack extension model. The tight sandstone horizontal well adopts a staged multi-cluster fracturing mode to fully utilize the reservoir, but not all perforation clusters can be simultaneously cracked due to the influence of ground stress and reservoir heterogeneity, and the cracking perforation clusters firstly enter an extension stage to generate induced stress, so that the in-situ stress of the stratum can be influenced, and the newly calculated cracking pressure of the follow-up uncracked perforation clusters is influenced. The method utilizes the crack extension pressure and the hole friction to realize real-time control on the crack initiation and extension sequence, realizes the competition initiation and extension of the multi-cluster jet holes of the compact sandstone horizontal well, and further improves the complexity of hydraulic cracks.
Assuming that m clusters of cracks exist in one section, after fracturing fluid enters a shaft, a certain cluster or part of clusters are firstly cracked, the firstly cracked cracks generate dominant channels, the fracturing fluid is mainly gathered in the dominant channels, and the firstly cracked perforation clusters enter an extension stage. For ultra-low permeability tight sandstone reservoirs, the fracture is long and narrow, which is described herein using a classical PKN model. The modeling process is described in detail below using three clusters as an example, and a schematic diagram is shown in fig. 2.
In the initial stage of fracturing, the bottom hole pressure is gradually increased along with continuous injection of fracturing fluid; the magnitude of the cracking pressure of each cluster calculated based on the early-stage flow dynamic allocation model is assumed to be the largest in the cracking pressure of the first cluster, the second cluster is the smallest in the cracking pressure of the third cluster, and therefore when the bottom hole pressure reaches the cracking pressure of the second cluster at first; at this time, the bottom hole pressure p w satisfies:
pfr1＞pfr3＞pw＞pfr2 (0-6)
Wherein p fr1 -the newly calculated cracking pressure of the first cluster, MPa;
p fr2 -newly calculated cracking pressure of the second cluster, MPa;
p fr3 -newly calculated cracking pressure of the third cluster, MPa.
After the second cluster is cracked, the fracturing fluid is continuously injected, and the cracks generated by the second cluster are continuously extended; at this time, the injected fracturing fluid enters the stratum through the holes of the second cluster, and in the process of extending the cracks of the second cluster, the bottom hole pressure is the sum of the minimum main stress of the reservoir, the net pressure in the cracks and the friction resistance of the perforation holes, so as to ensure the extension of the second cluster, and the bottom hole pressure is always lower than the cracking pressure of the first cluster and the third cluster, namely:
pfr1＞pfr3＞pw＝σh+pnet,2+ppf,2 (0-7)
Wherein p net,2 -the second cluster generates a net fluid pressure in the fracture, MPa;
p pf,2 -the pore friction of the second cluster, MPa.
It is apparent that equation (0-7) is the bottom hole pressure p w calculated using the second cluster extension process, which is also the fracture entry pressure p w,2, so equation (0-7) can be used to calculate the fluid pressure p w,i at the entry of the ith fracture.
Based on the fracture extension model, the net pressure in the fracture is related to the young's modulus of the reservoir, the poisson ratio of the reservoir, the viscosity of the fracturing fluid, the injection displacement of the fracturing fluid, the height of the hydraulic fracture and the half length of the fracture, namely:
Wherein Q 2 -displacement of the second cluster, m 3/min;
c-comprehensive fluid loss coefficient, m/min 1/2;
h f -hydraulic fracture height, m.
And the hydraulic fracture length is related to the Young's modulus, poisson's ratio, fracturing fluid injection displacement, fracturing fluid viscosity, hydraulic fracture height and fluid injection time of the reservoir:
The hydraulic fracture gap width is related to the Young's modulus of a reservoir, poisson's ratio, fracturing fluid injection displacement, fracturing fluid viscosity, hydraulic fracture gap height and fluid injection time:
After the crack generated by the second cluster extends for a period of time, judging the magnitude relation between the bottom hole pressure at the moment and the newly calculated cracking pressure of the first cluster and the third cluster under the influence of induced stress in real time; when the bottom hole pressure is further greater than the newly calculated cracking pressure of the third cluster, the third cluster cracks, i.e.:
pfr1＞pw＞pfr3 (0-11)
Immediately thereafter, the third cluster is burst extended and the burst extension process of the second cluster is repeated. At this moment, the second cluster and the third cluster are extended along with the increase of the liquid injection time, all generate induced stress, and the updated in-situ stress is obtained after the induced stress and the third cluster are overlapped. And calculating the new cracking pressure and the bottom hole pressure of the first cluster in real time on the basis of the new in-situ stress, and when the bottom hole pressure is larger than the newly calculated cracking pressure of the first cluster, the first cluster cracks and extends, so as to finally realize the competition cracking and expansion of the multi-cluster jet holes.
And constructing a hydraulic fracture induced stress model. The hydraulic fracture generated by the first fracture perforation cluster induces additional stress, changes the in-situ stress field and affects the subsequent fracture initiation and extension. However, because the fractures formed after hydraulic fracturing are not all vertical fractures due to the influences of drilling, ground stress azimuth and perforation, oblique fractures (fractures are not perpendicular to the wellbore direction) may occur, so that it is necessary to build an oblique fracture induced stress model and couple the oblique fracture induced stress model into a multi-cluster fracture competing fracture initiation and propagation model. On the basis of a homogeneous and isotropic two-dimensional plane hydraulic fracture model, a hydraulic fracture induced stress field model is established, and a Fourier transformation and complex transformation function are used for deducing an induced stress calculation expression.
The hydraulic fracture induced stress field model for this embodiment:
The stratum has a vertical hydraulic fracture (the limit condition that the minor half axis of the ellipse is zero) with the length of 2a (namely the fracture length is 2L f,i, which is abbreviated as 2a for the convenience of deduction); the tensile stress acting on the fracture surface is-p net, and the physical model is shown in fig. 3, and the corresponding boundary conditions are as follows:
Based on the elastic mechanics theory, the plate problem in the physical model belongs to the plane strain problem, and then the stress strain equation is as follows:
the equilibrium equation is as follows (physical force is not counted):
Let be the stress function of the plane problem, then:
two-dimensional double-tuning and equations describing the plane problem in elastic mechanics are introduced:
a fourier integral transformation is introduced:
fourier transform of ;
Is inverse fourier transformed;
i-imaginary units.
With reference to fig. 4, the two-dimensional vertical fracture induced stress field is obtained as:
wherein p net is the net pressure on the fracture face, MPa;
the a-split is half-length, i.e., L f,i, m.
The relationship between the geometric parameters is as follows:
If θ, θ 1 and θ 2 are negative, then θ+180°, θ 1 +180° and θ 2 +180° should be replaced, respectively. The above is a two-dimensional vertical fracture-induced stress model, and an oblique fracture-induced stress model is built on the basis of the model.
The crack propagation criteria of this embodiment are established. The multi-cluster crack competition initiation and propagation model relates to the problem of crack propagation, and the crack propagation criterion is one of core problems to be solved urgently. The propagation criteria require further explanation of the crack propagation conditions and propagation direction. Based on fracture mechanics theory, maximum circumferential stress theory is used herein as a crack propagation criterion.
The embodiment relates to the perforation cluster crack extension model:
After the multi-cluster cracks are cracked at the perforation holes, the connection near the well wall can be regarded as an I-type and II-type composite fracture problem, in the problem, the stress field near the tip of the cracks can be represented by K I、KII, and the expansion direction of the cracks can be calculated. Based on the theory of linear elastic fracture mechanics, and combined with the research results of Zhang Anqing et al, the expression of the K I、KII type strength factor is obtained:
Wherein K I -I type intensity factor, MPa.m 1/2;
K II -II type intensity factor, MPa.m 1/2;
p net (x) -the net pressure produced by the micro-segment x, MPa;
Sigma 1、σ3 -maximum principal stress and minimum principal stress, MPa;
and r-calculating the distance from the point to the center of the crack, and m.
The maximum circumferential stress theory holds that when the circumferential stress σ θ reaches a certain value, the crack breaks and propagates in the direction of the maximum circumferential stress. Based on fracture mechanics theory, solving a polar coordinate expression of circumferential stress at the crack tip:
the ultimate hoop stress when fracture failure occurs is:
Sigma θc -limit circumferential stress in the formula and MPa;
K Ic -fracture toughness of rock, MPa.m 1/2.
Union type (0-23) and formula (0-24), when σ θ≥σθc, crack propagation, namely:
At this time, an equivalent intensity factor is defined:
wherein K e is an equivalent strength factor, and MPa.m 1/2.
The maximum circumferential stress criterion is described by the equivalent strength factor:
Ke≥KIc (0-27)
the first derivative of the formula (0-23) is calculated to be 0, the second derivative is ensured to be smaller than 0, the crack extension direction angle is obtained, the schematic diagram is shown in fig. 5, and the calculation formula for obtaining theta is shown as follows:
After the model is built, the model can be compiled and built in an electronic device, and the electronic device comprises a processor and a memory, wherein the memory is used for storing executable instructions of the processor; the processor is configured to perform the tight hydrocarbon multi-fracture competitive onset bottom hole pressure prediction method.
In the electronic device, the processor 101 may include a central processing unit 101 (CPU), or an Application SPECIAL INTEGRATED Circuit (ASIC), or one or more integrated circuits configured to implement the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method.
The memory 102 may include mass storage 102 for data, which may include for data or instructions. By way of example, and not limitation, memory 102 may comprise a hard disk drive (HARD DISK DRIVE, HDD), a floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or a universal serial bus (Universal Serial Bus, USB) drive, or a combination of two or more of the foregoing. Memory 102 may include removable or non-removable (or fixed) media, where appropriate. The memory 102 may be internal or external to the data processing apparatus, where appropriate. In a particular embodiment, the memory 102 is a non-volatile solid-state memory 102. In a particular embodiment, the memory 102 includes read only memory 102 (ROM). The ROM may be mask programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these, where appropriate.
The processor 101 reads and executes the computer program instructions stored in the memory 102 to implement the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method described above.
In a further embodiment of the present electronic device 1, the present electronic device 1 may further comprise a communication interface 103 and a bus 104. As shown in fig. 5, the processor 101, the memory 102, and the communication interface 103 are connected to each other by a bus 104 and perform communication with each other.
The communication interface 103 is mainly used for realizing communication among various modules, devices, units and/or equipment required by the dense oil gas multi-crack competition cracking bottom hole pressure prediction method. The bus 104 includes hardware, software, or both, coupling the components of the present electronic device 1 to one another. By way of example, and not limitation, the buses may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an infiniband interconnect, a Low Pin Count (LPC) bus, a memory 102 bus, a micro channel architecture (MCa) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a video electronics standards association local (VLB) bus, or other suitable bus, or a combination of two or more of the above. Bus 104 may include one or more buses, where appropriate. Although a particular bus is described and illustrated, the present invention contemplates any suitable bus or interconnect.
Establishing a horizontal well sectional multi-cluster flow dynamic distribution model based on the friction of the shaft and the perforation holes and the coupling pressure flow relation; taking the heterogeneous reservoir physical properties and the ground stress difference into consideration, and establishing a fracture extension model and a fracture induced stress model of a fracture perforation cluster; and finally, coupling single-cluster fracture initiation, flow dynamic distribution, fracture initiation perforation cluster fracture extension and fracture induced stress models, and finally establishing a shale horizontal well multi-cluster perforation competition initiation and extension model. According to the fluid-driven cracking problem, the programming solution thought of the shale horizontal well multi-cluster perforation competition cracking and expansion model is obtained:
(1) Basic parameter input, namely basic parameters required by competition cracking and expansion model calculation, mainly comprises two major categories of stratum parameters and construction parameters. The stratum parameters mainly comprise three-way ground stress, stratum pressure, stratum physical parameters, tensile strength, poisson ratio, reservoir thickness, comprehensive compression coefficient and the like; the construction parameters mainly comprise viscosity of the fracturing fluid, construction displacement, comprehensive fluid loss coefficient of the fracturing fluid, the number of crack clusters, cluster spacing, construction time, perforation parameters, shaft parameters and the like.
(2) The initial flow distribution Q i is obtained, and the cracking sequence of each cluster is obtained, namely, an initial flow distribution is firstly assumed, the cracking pressure of each cluster is obtained by combining a seepage-stress cracking pressure prediction model, and the calculated bottom hole pressure is substituted into an equation (0-5) to see whether the pressure flow balance criterion is met. If yes, recording the initial flow distribution and the cracking sequence at the moment; if not, the flow allocation is changed and the calculation is continued until the condition is satisfied. The initial flow is obtained randomly, the general construction displacement is about 12-18 square/min, and the random number is between 12 and 18.
(3) On the premise of obtaining the cracking sequence of each cluster, the time step delta t of the subsequent crack extension is given.
(4) At a first time t 1, assuming flow distribution Q i, it is determined whether or not the crack is extended. Changing the flow distribution if not extending; if the crack extends, calculating the half-seam length and the net pressure of the first-crack perforation cluster, wherein the crack extending from the first-crack perforation cluster generates induced stress components to influence the ground stress of the rest clusters, so that the crack pressure is influenced. Substituting the bottom hole pressure generated by the calculated pre-cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster into an equation (0-5) to see whether the pressure flow balance criterion is met, and if so, increasing the time step delta t to start the calculation of the next moment; if not, the flow allocation is changed and the calculation is continued until the condition is satisfied.
(5) And when the bottom hole pressure calculated by adopting the cracking perforation cluster is greater than the new cracking pressure of a certain uncracked perforation cluster, the perforation cluster is cracked and enters an extension stage.
(6) And calculating the construction time, and judging whether the given construction time is reached. If the program is reached, ending the operation of the program, and further performing post-processing; if not, returning to the step (3), and calculating the competition cracking condition of the next time step until the construction time is over.
Based on the program solving thought, programming software is used for programming a shale horizontal well multi-cluster perforation competition cracking and expansion model program, and a multi-crack cracking and expansion dynamic simulation process is realized. The program operation flow chart is shown in fig. 6.
The following is a verification description by way of an example:
Based on the compact sandstone horizontal well multi-cluster perforation competition cracking and expanding model established by the invention, a sand-temple group X sandstone gas well in Sichuan basin and Sichuan middle area is selected as a basic parameter of simulation, and multi-cluster crack competition cracking and expanding rule analysis is carried out by taking each section of shooting three clusters commonly used on site as an example. It should be noted that, in the multi-cluster fracture propagation model established by most scholars in the past, each cluster is assumed to crack simultaneously, and perforation clusters may not crack simultaneously due to reservoir heterogeneity, ground stress difference and perforation pressure drop, that is, each cluster has a certain cracking order. For this purpose, 3 different permeability zones were set up around each of the three perforation clusters to describe physical heterogeneity, and specific parameters are shown in table 1.
Table1 table of basic parameters calculated for multiple crack competitive initiation and propagation models of sandstone gas wells
In the shale hydraulic fracturing construction process, along with gradual liquid injection of a shaft, the bottom hole starts to hold down pressure, and the bottom hole pressure gradually rises. When the bottom hole pressure reaches the minimum cluster of the cracking pressures in the three clusters, the cluster is cracked. Fig. 8 shows the bottom hole pressure, second cluster new fracture pressure and third cluster new fracture pressure over time over the first 15s (time locally exaggerated). The calculation result shows that at 0.66s, the bottom hole pressure reaches the cracking pressure 68.02MPa of the first cluster, and the first cluster is cracked at the moment; at the same time, the cracking pressure of the second cluster was 69.37MPa, while the cracking pressure of the third cluster was 72.12MPa. The main reason is that the first cluster has the largest permeability, the stratum has strong liquid absorption capacity, the effective stress is increased, the first cluster is easy to damage, and the cracking pressure is minimum.
And when the first cluster of cracks meet the expansion condition along with the increase of the injection time, the cracks are extended, and the bottom hole pressure at the moment is calculated based on the extension condition of the first cluster of cracks. It is the seam length and net pressure induced stress field generated by the first cluster of seam extension that affects the in situ stress distribution and thus the magnitude of the ground stress; while the change in ground stress causes the new cracking pressure of the unbroken clusters (second and third clusters) to change in real time, and then the new cracking pressure oscillates as shown in fig. 7 and 8. When at 14s, the bottom hole pressure is greater than the new fracture pressure of the third cluster, at which point the third cluster fractures and extends. Over time, the first and third clusters of cracks continue to propagate and continue to affect the change in the new initiation pressure of the second, unbroken cluster. Eventually, at 2210s, the bottom hole pressure is greater than the fracture initiation pressure of the second cluster, which extends.
The method for predicting the bottom hole pressure of the compact oil gas multi-crack competition cracking has at least the following beneficial effects:
(1) The invention can accurately calculate the bottom hole pressure and the change rule of the tight sandstone in the fracturing construction process, can predict whether the multiple cracks in the section can be normally opened, and provides a basis for the optimization of the subsequent perforation parameters.
(2) If the situation that the multi-cluster cracks can be cracked and effectively extended still cannot be realized by adjusting perforation parameters and construction parameters, temporary plugging agents can be added in the fracturing construction process to generate plugging pressure so as to improve bottom hole pressure, the aim that the perforation clusters can be cracked and extended effectively is achieved, a basis is provided for optimizing the adding amount of the subsequent temporary plugging agents, and the purpose of fully reforming the dessert of the reservoir is achieved.
In this embodiment, an electronic device includes a processor and a memory; the memory is used for storing processor executable instructions; the processor is configured to perform the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method described above. By adopting the electronic device, the magnitude and the change rule of the bottom hole pressure in the fracturing pump injection process can be accurately predicted, so that the high-efficiency modification parameters of the tight sandstone can be better optimized.
The embodiment also provides a computer readable storage medium comprising a stored computer program, wherein the program executes the method for predicting the bottom hole pressure of the tight oil and gas multi-crack competition cracking during running
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (9)
1. The method for predicting the bottom hole pressure of the multi-crack competition cracking of the compact oil gas is characterized by comprising the following steps:
s1, acquiring initial flow distribution data and acquiring the cracking sequence of each cluster;
S2, giving a time step of extending a subsequent crack according to the crack starting sequence of each cluster;
S3, in the time step, when the time step is set at the first moment, assuming a flow distribution value, judging whether a crack extends or not;
s3.1, if the flow distribution is not extended, changing the flow distribution;
S3.2, if the well bottom pressure generated by the first cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster are obtained, and whether the well bottom pressure generated by the first cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion is judged;
S4, after the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion, acquiring the half-joint length and the net pressure of the cracking perforation cluster, the induced stress and the new cracking pressure of the non-cracking perforation cluster at different moments according to the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster;
S5, when the bottom hole pressure calculated according to the half-seam length, the net pressure and the generated induced stress of the pre-cracking perforation cluster is larger than the new cracking pressure of any one of the non-cracking perforation clusters, the judgment that the perforation cluster is cracked and enters an extension stage can be obtained;
s6, calculating construction time, and judging whether the given construction time is reached;
S6.1, if the given construction time is reached, completing the whole prediction step;
And S6.2, if the given construction time is not reached, returning to the step S3 until the construction time is over.
2. The tight oil and gas multi-fracture competitive initiation bottom hole pressure prediction method according to claim 1, wherein,
The step of judging whether the bottom hole pressure generated by the first cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion comprises the following steps:
If the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster meet the pressure flow balance criterion, increasing the time step and performing step S4;
if the bottom hole pressure generated by the cracking perforation cluster and the new cracking pressure of the non-cracking perforation cluster do not meet the pressure flow balance criterion, changing the flow distribution until the conditions are met, and then performing step S4.
3. The tight oil and gas multi-fracture competitive initiation bottom hole pressure prediction method according to claim 1, wherein,
Before the prediction is carried out by the tight oil gas multi-crack competition cracking bottom hole pressure prediction method, a tight sandstone horizontal well seepage-stress cracking pressure prediction model, a hydraulic fracture induced stress model, a multi-cluster fracture flow dynamic distribution model and a perforation cluster fracture extension model are required to be constructed;
According to the multi-cluster crack flow dynamic distribution model, the perforation cluster crack extension model and the hydraulic crack induced stress model, a shale horizontal well multi-cluster perforation competition cracking and extension model is constructed, and initial flow distribution data and the cracking order of each cluster are obtained according to the shale horizontal well multi-cluster perforation competition cracking and extension model.
4. The method for predicting the bottom hole pressure of multiple cracks in tight oil and gas according to claim 3, wherein,
The construction of the multi-cluster fracture flow dynamic distribution model, the perforation cluster fracture extension model and the hydraulic fracture induced stress model comprises the following steps:
Establishing a horizontal well sectional multi-cluster crack flow dynamic distribution model according to the friction of the shaft and the perforation, and obtaining flow dynamic distribution data by the horizontal well sectional multi-cluster crack flow dynamic distribution model;
constructing a fracture extension model and a fracture induced stress model of a fracture-initiating perforation cluster according to the heterogeneous physical properties and the ground stress difference of the reservoir;
and (3) coupling single-cluster fracture initiation data, flow dynamic allocation data, a fracture initiation perforation cluster fracture extension model and a fracture induced stress model, and constructing a shale horizontal well multi-cluster perforation competition initiation and extension model.
5. The tight oil and gas multi-fracture competitive initiation bottom hole pressure prediction method according to claim 4, wherein,
The construction of the multi-cluster fracture flow dynamic distribution model comprises the step of coupling the inlet flow of each cluster of fractures and the total pressure of the root end of the horizontal well.
6. The tight hydrocarbon multi-fracture competitive initiation bottom hole pressure prediction method of claim 3, wherein the multi-cluster fracture flow dynamic allocation model is:
Q-total displacement of fracturing fluid injection, m 3/min;
Q i -the flow of the ith crack, m 3/min;
m-total cluster number in the same fracturing section, and dimensionless;
p 0 -fluid pressure at the heel end of the horizontal well, MPa;
pressure loss of p cf,i -ith fracture along the wellbore, MPa;
p w,i -fluid pressure at entry to the ith fracture, MPa;
p pf,i -ith crack perforation friction resistance, MPa;
d p,i -ith crack perforation hole diameter, m;
C d,i -ith crack aperture flow coefficient, dimensionless;
ρ s —density of fracturing fluid, kg/m 3;
n p,i -the number of holes of the ith crack, and has no dimension.
7. The tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method of claim 3, wherein the perforation cluster fracture propagation model is:
pfr1＞pfr3＞pw＞pfr2
p w -bottom hole pressure, MPa;
p fr1 -newly calculated cracking pressure for the first cluster, MPa;
p fr2 -newly calculated cracking pressure for the second cluster, MPa;
p fr3 -newly calculated cracking pressure for the third cluster, MPa;
pfr1＞pfr3＞pw＝σh+pnet,2+ppf,2
p net,2 -the second cluster generates net fluid pressure in the fracture, MPa;
p pf,2 -the pore friction of the second cluster, MPa;
sigma h -minimum horizontal principal stress, MPa;
Q 2 -displacement of the second cluster, m 3/min;
c-comprehensive fluid loss coefficient, m/min 1/2;
H f —hydraulic fracture height, m;
t-liquid injection time, min;
E-Young's modulus;
mu-poisson ratio, dimensionless;
V-poisson ratio, dimensionless;
L f,2 -hydraulic fracture length, m;
w f,2 -hydraulic fracture width, m.
8. An electronic device, comprising:
A processor;
A memory for storing processor-executable instructions;
The processor configured to perform the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method of any one of claims 1-5.
9. A computer-readable storage medium, characterized in that,
A computer program comprising a storage, said program when run executing the tight hydrocarbon multi-fracture competitive fracture bottom hole pressure prediction method of any of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111401787.9A CN113982568B (en) | 2021-11-19 | 2021-11-19 | Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111401787.9A CN113982568B (en) | 2021-11-19 | 2021-11-19 | Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113982568A CN113982568A (en) | 2022-01-28 |
| CN113982568B true CN113982568B (en) | 2024-04-16 |
Family
ID=79750228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111401787.9A Active CN113982568B (en) | 2021-11-19 | 2021-11-19 | Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113982568B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116415519B (en) * | 2023-03-09 | 2024-03-12 | 同济大学 | Shale gas reservoir multi-cluster hydraulic fracture synchronous competition expansion numerical simulation method and system |
| CN116877067B (en) * | 2023-07-18 | 2024-03-12 | 重庆地质矿产研究院 | Method for predicting hydraulic fracturing generated cracks and swept area fluid pressure |
| CN117684938B (en) * | 2024-02-04 | 2024-04-26 | 新疆石油管理局有限公司 | Reservoir transformation method and device for directional pulse jet flow control seam height |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160326853A1 (en) * | 2015-05-08 | 2016-11-10 | Schlumberger Technology Corporation | Multiple wellbore perforation and stimulation |
| WO2016192077A1 (en) * | 2015-06-04 | 2016-12-08 | 中国石油集团川庆钻探工程有限公司长庆井下技术作业公司 | Method for establishing and solving numerical well-testing model of horizontal well for tight gas hydraulic fracturing |
| CN106894793A (en) * | 2017-03-03 | 2017-06-27 | 西南石油大学 | The many cluster perforating and fracturing optimization method and devices of horizontal well in segments |
| CN109812247A (en) * | 2019-02-21 | 2019-05-28 | 中国石油天然气股份有限公司 | Perforation and fracturing method for improving transformation degree of compact oil horizontal well |
| CN112096362A (en) * | 2020-09-27 | 2020-12-18 | 西南石油大学 | Unconventional reservoir multi-cluster perforation competition cracking and expansion simulation method and device |
| CN112949129A (en) * | 2021-03-03 | 2021-06-11 | 西南石油大学 | Deep shale horizontal well fracturing multi-cluster fracture asynchronous initiation extension calculation method |
| CN113389534A (en) * | 2021-07-21 | 2021-09-14 | 西南石油大学 | Method for predicting propagation of horizontal well intimate-cutting fracturing fracture and optimizing design parameters |
-
2021
- 2021-11-19 CN CN202111401787.9A patent/CN113982568B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160326853A1 (en) * | 2015-05-08 | 2016-11-10 | Schlumberger Technology Corporation | Multiple wellbore perforation and stimulation |
| WO2016192077A1 (en) * | 2015-06-04 | 2016-12-08 | 中国石油集团川庆钻探工程有限公司长庆井下技术作业公司 | Method for establishing and solving numerical well-testing model of horizontal well for tight gas hydraulic fracturing |
| CN106894793A (en) * | 2017-03-03 | 2017-06-27 | 西南石油大学 | The many cluster perforating and fracturing optimization method and devices of horizontal well in segments |
| CN109812247A (en) * | 2019-02-21 | 2019-05-28 | 中国石油天然气股份有限公司 | Perforation and fracturing method for improving transformation degree of compact oil horizontal well |
| CN112096362A (en) * | 2020-09-27 | 2020-12-18 | 西南石油大学 | Unconventional reservoir multi-cluster perforation competition cracking and expansion simulation method and device |
| CN112949129A (en) * | 2021-03-03 | 2021-06-11 | 西南石油大学 | Deep shale horizontal well fracturing multi-cluster fracture asynchronous initiation extension calculation method |
| CN113389534A (en) * | 2021-07-21 | 2021-09-14 | 西南石油大学 | Method for predicting propagation of horizontal well intimate-cutting fracturing fracture and optimizing design parameters |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113982568A (en) | 2022-01-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113982568B (en) | Method for predicting bottom hole pressure of tight oil gas multi-crack competition cracking | |
| CN110608024B (en) | Volume fracturing method for improving filling efficiency of micro-support system by deep shale gas | |
| CN109992864A (en) | Unconventional dual media reservoir volume fracturing numerical simulation and parameter optimization method | |
| US20110276318A1 (en) | Method for determining the closure pressure of a hydraulic fracture | |
| CN109359376B (en) | Method for judging and identifying expansion of hydraulic fracturing fracture on natural fracture interface of shale reservoir | |
| CN112096362B (en) | Unconventional reservoir multi-cluster perforation competition cracking and expansion simulation method and device | |
| CN109800523B (en) | Non-orthogonal natural fracture opening determination method under hydraulic fracture temporary plugging condition | |
| Furui et al. | A comprehensive model of high-rate matrix acid stimulation for long horizontal wells in carbonate reservoirs | |
| CN111271042A (en) | Displacement optimization method for forming complex fracture network by hydraulic fracturing of natural fracture development reservoir | |
| CN111878051A (en) | Shale reservoir seam control uniform expansion fracturing method | |
| CN111472730B (en) | Large-section multi-cluster fracturing perforation scheme determination method | |
| Zhu et al. | Multicluster fractures propagation during temporary plugging fracturing in naturally fractured reservoirs integrated with dynamic perforation erosion | |
| Chang et al. | Simulation and optimization of fracture pattern in temporary plugging fracturing of horizontal shale gas wells | |
| Shan et al. | A new finite element method to predict the fracture initiation pressure | |
| CN116992618A (en) | Shale horizontal well multi-cluster jet hole competition cracking and expansion simulation method | |
| Sesetty et al. | Modeling dense-arrays of hydraulic fracture clusters: Fracture complexity, net pressure and model calibration | |
| CN111810107A (en) | Method for determining optimal time for repeated fracturing of group wells | |
| CN116717224A (en) | Fracturing productivity prediction method for complex fracture network of hypotonic tight reservoir | |
| CN110344800B (en) | Staged fracturing method for horizontal well | |
| CN112377183B (en) | Method and device for constructing multi-hole multi-seam carbonate reservoir yield analysis model | |
| CN114575812B (en) | Shale reservoir gas well fracturing scheme determination method and device | |
| CN111396014B (en) | Thin interbed reservoir reformation method, device and equipment | |
| CN113530534B (en) | Reservoir reconstruction method and device | |
| CN114528715A (en) | Optimization method for temporary plugging knots and temporary plugging balls in horizontal well multi-cluster steering fracturing | |
| Cui et al. | Experimental study on fracture propagation morphology of deviated well in tight reservoir |
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 |