CN108304609B - Method for judging steering capacity of tight reservoir fracture of oil and gas well - Google Patents
Method for judging steering capacity of tight reservoir fracture of oil and gas well Download PDFInfo
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Abstract
A method for judging the steering capacity of tight reservoir fractures of an oil and gas well comprises the following steps: 1) selecting four factors of initial crack inclination angle, ground stress difference, rock fracture toughness and fluid pressure, and designing an orthogonal test scheme as different input parameters; 2) simulating a steering crack expansion path by using an expansion finite element unit method by taking the parameters as input parameters; 3) calculating the size of a corresponding fracture angle according to the turning crack path in the step 2; 4) carrying out normalization processing on the four factors; 5) establishing a steering capacity evaluation model, wherein a steering capacity index DI is the sum of 4 normalization factors; 6) judging the steering capacity; 7) and (4) drawing a curve between the fracture turning ability index DI and the size of the fracture angle corresponding to the step 3. The method can quickly and accurately obtain the steering capacity of the compact reservoir fracture, does not need to develop an indoor large-scale physical model experiment, and reduces the experiment cost.
Description
Technical Field
The invention belongs to the field of hydraulic fracturing in oil and gas engineering, and particularly relates to a method for judging the steering capacity of a tight reservoir fracture of an oil and gas well.
Background
Reservoir matrixes such as shale oil gas and dense oil gas have low permeability, and a complex fracture network is formed by a volume fracturing modification technology to perform efficient development. The diversion fracturing modification is an important means for enhancing the network expansion and control degree of cracks, when objective factors such as local stress difference are not beneficial to crack diversion, manual additional shielding can be introduced through the temporary blocking diverting agent to block the cracks and high-seepage channels formed previously, so that the diversion fracturing can be controlled, and the modification range and effect can be improved.
Zhou et al use formation temperature automatic degradable fibers in the diversion acid fracturing construction of carbonate oil and gas reservoirs to increase the probability of communicating with the fracture body, and field tests show that the fibers can effectively block the fracture temporarily and force the fracture to divert; the indoor experiment and the field construction show that: the pressure is increased, and the temporary plugging of the cracks is effective. Cohen et al evaluated the fibers to effectively block the blastholes temporarily by a temporary plugging capability evaluation experimental device, so that the acid liquid is diverted; two key parameters that control diversion are fiber cake permeability and initial fluid loss. Allison et al developed a degradable deformable particle diverter having a density of 1.25g/cm3Can be carried by a low viscosity liquid or a crosslinking system liquid; particles with two particle sizes are mixed for use, and the particles deform under the stratum condition to form a compact shielding layer; the method is used for Barnett shale repeated fracturing construction, and the steering effect is good. Bryant simulated the fracture competition cracking process in transient locked-in diverting fracturing by UTWID software and performed sensitivity analysis on several key design parameters. The results indicate that the diverter can stop the propagation of the already-propagated fracture, thereby initiating the propagation of the higher fracture pressure fracture.
Determining the steering capacity of the reservoir fracture can provide a basic criterion for steering fracturing reconstruction, and at present, an effective method for judging the steering capacity of the tight reservoir fracture is not provided. The invention provides a method for judging the steering capacity of a compact reservoir fracture, which can be used for judging whether the compact reservoir is suitable for a temporary blocking steering fracturing technology.
Disclosure of Invention
In order to achieve the purpose, the invention provides a method for judging the steering capacity of a tight reservoir fracture of an oil and gas well by considering four factors of artificial fracture inclination angle, ground stress difference, fracture toughness and fluid pressure, and the method comprises the following steps:
1) selecting four main factors of initial crack inclination angle, ground stress difference, rock fracture toughness and fluid pressure, and carrying out 4-factor 3 horizontal L9(34) Designing an orthogonal test scheme to serve as different input parameters;
2) taking the orthogonal test scheme in the step 1) as an input parameter, and simulating a steering crack expansion path by using an expansion finite element unit method;
3) defining a fracture angle as an included angle between the turning fracture and the initial artificial fracture, and calculating the size of the corresponding fracture angle according to the path of the turning fracture in the step 2);
4) the 4 factors are normalized, and the formula is as follows:
wherein, Xi(i is 1,2,3 and 4) respectively represents the numerical values of four factors of initial fracture inclination angle, earth stress difference, rock fracture toughness and fluid pressure in the step 1; that is to say X1Representing the initial crack dip angle as an angle value; x2The difference in ground stress is expressed in mpa; x3The fracture toughness of rock is expressed in MPa.m1/2I.e. mpa.m1/2；X4Fluid pressure in the fracture expressed in MegaPascals, XiminAnd XimaxRespectively representing the minimum value and the maximum value of each factor; xidNormalizing the processed value for each factor; because the fluid pressure, the rock fracture toughness and the steering capacity are in positive correlation, and the initial fracture inclination angle and the earth stress difference are in negative correlation, the two factors of the fluid pressure and the rock fracture toughness are normalized by a formula (1), and the two factors of the initial fracture inclination angle and the earth stress difference are normalized by a formula (2);
5) considering the four factors into the mathematical model, establishing a steering capacity judging model to judge the steering capacity of the crack, wherein the calculation formula is as follows:
wherein DI is a steering ability index, and the steering ability index DI is the sum of normalized horizontal geostress difference, normalized initial artificial fracture dip angle, normalized rock fracture toughness and normalized intra-fracture flow pressure;
6) judging the steering capacity: the value range of each normalized crack steering ability influence factor is 0-1, so that the change range of the crack steering ability index is 0-4; the crack steering ability index DI is 4.0, which indicates that the crack steering ability is strongest; if DI is 0, the fracture steering ability is the worst; the larger the DI value, the more likely the crack is to be deflected;
7) and (3) drawing a curve corresponding to the fracture turning ability index DI and the size of the fracture angle corresponding to the step 3), and if positive correlation is presented between the fracture turning ability index DI and the size of the fracture angle corresponding to the step 3), the turning ability index is reasonable to calculate, namely the larger the turning fracture angle is, the more easily the fracture is turned.
Preferably, the tight reservoir comprises a dry hot rock, a shale gas, coal bed gas or tight oil and gas reservoir in an unconventional oil and gas reservoir, and a low-permeability or ultra-low permeability reservoir in a conventional oil and gas reservoir.
Preferably, the oil and gas well comprises a vertical well, a horizontal well or a slant well in the compact reservoir.
Preferably, the fracture turning ability index DI has a positive correlation with the corresponding fracture angle size, i.e., the larger the turning fracture angle, the more easily the fracture is turned.
Preferably, the larger the DI value of the fracture diverting capability index indicates that the fracture is more easily diverted, and the more suitable the tight reservoir is to apply the temporary block diverting fracturing technology.
For example, the fluid pressure X in the fracture4Normalization is performed using equation (2), i.e.
Thereby obtainingTo the fluid pressure X in the fracture4Dimensionless quantity X4dWherein X is4max、X4minRespectively representing the fluid pressure X in the fracture4Element maximum and minimum values of the vector; fracture toughness X of rock3Normalization is performed using equation (2), i.e.
Thereby obtaining the fracture toughness X of the rock3Dimensionless quantity X3dWherein X is3max、X3minRespectively showing the fracture toughness X of the rock in the fracture3Element maximum and minimum values of the vector;
initial crack dip X1Normalization is performed using equation (1), i.e.
Thereby obtaining an initial crack dip angle X1Dimensionless quantity X1dWherein X is1max、X1minRespectively represent initial crack inclination angles X1Element maximum and minimum values of the vector; horizontal principal stress difference X2Normalization is performed using equation (1), i.e.
Thereby obtaining the horizontal main stress difference X2Dimensionless quantity X2dWherein X is2max、X2minRespectively representing the horizontal principal stress difference X2The element maximum, minimum of the vector.
The invention has the following beneficial effects:
by adopting the scheme, the steering capacity of the compact reservoir cracks can be quickly and accurately obtained, an indoor large-scale physical model experiment is not required to be carried out, and the expensive cost brought by the experiment is reduced.
Drawings
FIG. 1 is a graph of fracture steering ability index versus fracture angle.
In fig. 1, the abscissa is a fracture steering ability index, dimensionless; the ordinate is the angle of rupture in degrees (not radians).
Detailed Description
Considering 4 main factors of initial fracture inclination angle, ground stress difference, rock fracture toughness and fluid pressure, the initial fracture inclination angle is respectively 30 degrees, 45 degrees and 60 degrees, the horizontal ground stress difference is respectively 0 MPa, 5 MPa and 10 MPa, and the fracture toughness is respectively 0 MPa-m1/20.5 MPa.m1/2And 1 MPa.m1/2Three levels, 60 MPa, 70 MPa and 80 MPa for the fluid pressure in the fracture, respectively, were carried out at 4-factor 3 level L9 (3)4) Designing an orthogonal test scheme to serve as different input parameters; simulating a steering crack extension path by using an extension finite element method, defining a fracture angle as an included angle between a steering crack and an initial artificial crack, obtaining the size of the fracture angle according to the steering crack path in the step 2, then performing normalization processing by using the 4 factors of the formula (1) to the formula (2), considering the four factors into a mathematical model, establishing a steering capacity judgment model, calculating the size of a steering capacity index by using the formula (3), and obtaining the result shown in the table 1:
using the new model presented above, the steering ability index was calculated from the parameters in table 1, and the relationship between the steering ability index DI and the break angle was plotted, as shown in fig. 1. It can be seen that a good positive linear relationship exists between the steering capacity index and the fracture angle, which shows the reliability and the rationality of the steering capacity judgment model.
TABLE 1 fracture Angle of steering crack and index of steering Capacity at different factor levels
Claims (5)
1. A method for judging the steering capacity of tight reservoir fractures of an oil and gas well comprises the following steps:
1) selecting four main factors of initial crack inclination angle, ground stress difference, rock fracture toughness and fluid pressure, and carrying out 4-factor 3 horizontal L9(34) Orthogonal test protocolAs different input parameters;
2) taking the orthogonal test scheme in the step 1) as an input parameter, and simulating a steering crack expansion path by using an expansion finite element unit method;
3) defining a fracture angle as an included angle between the turning crack and the initial artificial crack, and calculating the size of the corresponding fracture angle according to the expanding path of the turning crack in the step 2);
4) the four main factors are normalized, and the formula is as follows:
wherein, XiRespectively representing the numerical values of four main factors of initial fracture inclination angle, earth stress difference, rock fracture toughness and fluid pressure in the step 1, wherein i is 1,2,3 and 4; that is to say X1Representing the initial crack dip angle as an angle value; x2The difference in ground stress is expressed in mpa; x3The fracture toughness of rock is expressed in MPa.m1/2I.e. mpa.m1/2；X4Fluid pressure in the fracture expressed in MegaPascals, XiminAnd XimaxRespectively representing the minimum value and the maximum value of each factor; xidNormalizing the processed value for each factor; because the fluid pressure, the rock fracture toughness and the steering capacity are in positive correlation, and the initial fracture inclination angle and the earth stress difference are in negative correlation, the two factors of the fluid pressure and the rock fracture toughness are normalized by a formula (1), and the two factors of the initial fracture inclination angle and the earth stress difference are normalized by a formula (2);
5) considering the four main factors into the mathematical model, establishing a steering capacity judging model to judge the steering capacity of the crack, wherein the calculation formula is as follows:
wherein DI is a steering ability index, and the steering ability index DI is the sum of normalized horizontal geostress difference, normalized initial artificial fracture dip angle, normalized rock fracture toughness and normalized intra-fracture flow pressure;
6) judging the steering capacity: the value range of each normalized crack steering ability influence factor is 0-1, so that the change range of the crack steering ability index is 0-4; the crack steering ability index DI is 4.0, which indicates that the crack steering ability is strongest; if DI is 0, the fracture steering ability is the worst; the larger the DI value, the more likely the crack is to be deflected;
7) and (3) drawing a curve corresponding to the fracture turning ability index DI and the size of the fracture angle corresponding to the step 3), and if positive correlation is presented between the fracture turning ability index DI and the size of the fracture angle corresponding to the step 3), the turning ability index is reasonable to calculate, namely the larger the turning fracture angle is, the more easily the fracture is turned.
2. The method of claim 1, wherein the tight reservoir comprises a hot dry rock, a shale gas, coal bed gas, or tight hydrocarbon reservoir in an unconventional hydrocarbon reservoir, a low permeability or ultra-low permeability reservoir in a conventional hydrocarbon reservoir.
3. The method of claim 1 or 2, wherein the oil or gas well comprises a vertical well, a horizontal well or a deviated well in the tight reservoir.
4. The method of claim 1 or 2, wherein: the fracture turning ability index DI and the corresponding fracture angle magnitude exhibit a positive correlation, i.e., the larger the turning fracture angle, the more easily the fracture is turned.
5. The method of claim 1 or 2, wherein: the larger the DI value of the fracture steering ability index is, the more easy the fracture is to turn, and the more suitable the compact reservoir stratum is to apply the temporary blocking steering fracturing technology.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106398672A (en) * | 2016-09-07 | 2017-02-15 | 中国石油化工股份有限公司 | Preparation method of water soluble phenolic resin crosslinking agent for temporary plugging steering acidizing |
| CN106543996A (en) * | 2016-10-24 | 2017-03-29 | 中国石油大学(华东) | Diversion agent and its using method are temporarily blocked up in a kind of acidifying |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106398672A (en) * | 2016-09-07 | 2017-02-15 | 中国石油化工股份有限公司 | Preparation method of water soluble phenolic resin crosslinking agent for temporary plugging steering acidizing |
| CN106543996A (en) * | 2016-10-24 | 2017-03-29 | 中国石油大学(华东) | Diversion agent and its using method are temporarily blocked up in a kind of acidifying |
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| 纤维强制裂缝转向规律实验及现场试验;汪道兵等;《东北石油大学学报》;20160630;第1-5页 * |
| 纤维暂堵形成流动阻力数学模型研究;梅艳等;《中国石油和化工标准与质量》;20140303;第1页 * |
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Effective date of registration: 20231027 Address after: 102617 Beijing Daxing District Huangcun Qingyuan Road No. 19 Patentee after: BEIJING INSTITUTE OF PETROCHEMICAL TECHNOLOGY Patentee after: China University of Petroleum (Beijing) Address before: 102617 Beijing Daxing District Huangcun Qingyuan Road No. 19 Patentee before: BEIJING INSTITUTE OF PETROCHEMICAL TECHNOLOGY |