CN114086946B - Crack height determining method for crack - Google Patents
Crack height determining method for crack Download PDFInfo
- Publication number
- CN114086946B CN114086946B CN202010854615.6A CN202010854615A CN114086946B CN 114086946 B CN114086946 B CN 114086946B CN 202010854615 A CN202010854615 A CN 202010854615A CN 114086946 B CN114086946 B CN 114086946B
- Authority
- CN
- China
- Prior art keywords
- fracture
- pressure
- height
- stratum
- seam height
- 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
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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 DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
Abstract
The disclosure provides a fracture height determining method for a fracturing fracture, and belongs to the technical field of fracturing. The method is suitable for a computer and comprises the following steps: obtaining the horizontal minimum principal stress of each stratum, the thickness of each stratum, the depth of the middle position of a fracture, the original fracture height of the fracture, the density of fracturing fluid, the pumping pressure of the fracturing fluid at a perforation position and the depth of the perforation position; establishing a stratum model and dividing the stratum model into a plurality of grids; correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid; calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the fracturing fluid pump pressure at the perforation position and the perforation position depth; calculating to obtain a tip stress intensity factor value of the fracture according to the original joint height and the fluid net pressure of each grid; and correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture. The present disclosure may improve seam height accuracy in determining a fracture.
Description
Technical Field
The disclosure belongs to the technical field of fracturing, and particularly relates to a fracture height determining method of a fracturing fracture.
Background
Hydraulic fracturing is a high-efficiency technique for increasing storage and production, and is widely applied to the reconstruction of unconventional oil and gas reservoirs. In the implementation of hydraulic fracturing, the fracture height of the fracture needs to be determined.
In the related art, the theory of the line elastic fracture mechanics is generally employed to determine the seam height of the fracture.
However, the formation rock has elastoplasticity, i.e. shows elasticity or plasticity under different conditions. For a high-stress multi-layering complex stratum, when a fracture crack is expanded in stratum rock, the stress concentration phenomenon exists at the tip of the fracture crack, the stratum rock is converted into plasticity from brittleness, and if the range of the plasticity area is small, the stratum rock can be treated by a linear elastic fracture mechanical method after correction. If the size of the plastic region is too large, the theory of the elastic fracture mechanics of the wire is no longer applicable, resulting in inaccurate seam height of the fracture.
Disclosure of Invention
The embodiment of the disclosure provides a seam height determining method for a crack, which can improve the seam height accuracy of determining the crack. The technical scheme is as follows:
the embodiment of the disclosure provides a seam height determining method of a crack, which is applicable to a computer, and comprises the following steps:
obtaining the horizontal minimum principal stress of each stratum, the thickness of each stratum, the depth of the middle position of a fracture, the original fracture height of the fracture, the density of fracturing fluid, the pumping pressure of the fracturing fluid at a perforating position and the depth of the perforating position;
establishing a stratum model, wherein the stratum model comprises a plurality of stratum;
dividing the stratigraphic model into a plurality of grids;
correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid;
calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pump pressure and the perforation position depth;
calculating to obtain a tip stress intensity factor value of the fracture according to the original joint height and the fluid net pressure of each grid;
correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the crack;
determining a relation curve according to the corresponding relation between the correction joint height and the perforation position fracturing fluid pump pressure;
and acquiring construction pump entry pressure, and determining the actual seam height of the crack corresponding to the construction pump entry pressure according to the relation curve.
Further, the dividing the stratigraphic model into a plurality of grids includes:
determining a perforation position according to the perforation position depth;
determining a unidirectional number of the grids, wherein the unidirectional number is the number of the grids required to be divided between the perforation positions and the top boundary of the stratum model or between the perforation positions and the bottom boundary of the stratum model;
and dividing the area between the perforation position and the top boundary of the stratum model and the area between the perforation position and the bottom boundary of the stratum model into a plurality of grids respectively according to the unidirectional quantity and taking the perforation position as a reference.
Further, the unidirectional number is set to 400 to 600.
Further, the net fluid pressure satisfies the following equation:
wherein p is net (x) For the net fluid pressure, ρ is the fracturing fluid density, g is the gravitational acceleration, p ref Pumping fracturing fluid into the perforation position, d mid D is the depth of the middle position of the crack ref For the depth of the perforation location,the horizontal minimum principal stress of the formation is the i-th layer.
Further, the tip stress intensity factor value satisfies the following formula:
wherein K is I For the tip stress intensity factor value, C is the half value of the original stitch height, p net (x) D is a differential sign for the net pressure of the fluid.
Further, the correcting the original slit height according to the tip stress intensity factor value to determine a corrected slit height of the fracture comprises:
determining the stratum where the tip of the fracture is located according to the tip stress intensity factor value;
determining an upper correction value and a lower correction value of the fracture according to the tip stress intensity factor value and the horizontal minimum principal stress of the stratum where the tip of the fracture is located;
and correcting the original seam height according to the upper correction value and the lower correction value to determine the corrected seam height of the crack.
Further, the upper correction value and the lower correction value satisfy the following formula:
wherein e d For the lower correction value e u For the upper correction value, K I+ For the stress intensity factor value, K, of the lower tip of the fracture I- For the upper tip stress intensity factor value of the fracture,the horizontal minimum principal stress of the formation is the i-th layer.
Further, the correction slit height satisfies the following formula:
A＝2C+e d +e u ；
wherein A is the corrected slot height, C is the half value of the original slot height, e d For the lower correction value e u For the upper correction value.
Further, the obtaining the construction pump pressure, and determining the actual seam height of the crack corresponding to the construction pump pressure according to the relation curve, includes:
calculating to obtain the corresponding perforation position fracturing fluid pumping pressure according to the construction pumping pressure;
and determining the actual seam height of the fracturing fluid at the perforation position corresponding to the construction pump pressure according to the construction pump pressure and referring to the relation curve.
Further, according to the construction pump-in pressure, the perforating position fracturing fluid pump-in pressure meets the following formula:
P pump ＝P n -ΔP h +ΔP c +ΔP t ；
wherein P is pump For the construction pump to pump in pressure, P n Pumping pressure, delta P, of fracturing fluid into the perforation location h Is hydrostatic column pressure，ΔP c For the loss pressure of the nozzle, deltaP t Pressure is lost for the string.
The technical scheme provided by the embodiment of the disclosure has the beneficial effects that at least:
when the seam height of the fracturing seam is determined by the seam height determining method of the fracturing seam provided by the embodiment of the disclosure, firstly, the horizontal minimum main stress of each stratum, the thickness of each stratum, the depth of the middle position of the fracturing seam, the original seam height of the fracturing seam, the density of fracturing fluid, the pumping pressure of the fracturing fluid at the perforating position and the depth of the perforating position are obtained to provide a data base for the subsequent steps. And then, establishing a stratum model, dividing the stratum model into a plurality of grids, and correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid. This may provide a model basis for subsequent steps. And then, calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pump pressure and the perforation position depth, and calculating to obtain the tip stress intensity factor value of the fracturing crack according to the original joint height and the fluid net pressure of each grid. This can provide a data basis for subsequent corrections to the original seam height. And then, correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture. The corrected seam height is the seam height of the crack obtained after the original seam height is corrected. And determining a relation curve according to the corresponding relation between the correction joint height and the pressure of the fracturing fluid pumped into the perforation position. And finally, acquiring the construction pump pressure, and determining the actual joint height of the crack corresponding to the construction pump pressure according to the relation curve.
That is, according to the method for determining the seam height of the fracturing seam provided by the embodiment of the disclosure, the original seam height is corrected through the tip stress intensity factor value, so that the accuracy of the relationship curve between the corrected seam height and the perforation position fracturing fluid pumping pressure obtained later is high, and then after the construction pumping pressure is known, the accurate actual seam height of the fracturing seam can be obtained according to the relationship curve.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a flow chart of a method for determining the seam height of a fracture provided in an embodiment of the present disclosure;
FIG. 2 is a flow chart of another method of determining the seam height of a fracture provided by an embodiment of the present disclosure;
FIG. 3 is a graph of a seam height correction physical model of a fracture provided by an embodiment of the present disclosure;
FIG. 4 is a graph of corrected slot height versus perforating position fracturing fluid pump-in pressure provided by embodiments of the present disclosure.
Detailed Description
For the purposes of clarity, technical solutions and advantages of the present disclosure, the following further details the embodiments of the present disclosure with reference to the accompanying drawings.
The embodiment of the disclosure provides a seam height determining method of a fracture, fig. 1 is a flowchart of the seam height determining method, and as shown in fig. 1, the seam height determining method includes:
step 101: the method comprises the steps of obtaining the horizontal minimum principal stress of each stratum, the thickness of each stratum, the depth of the middle position of a fracture, the original fracture height of the fracture, the density of fracturing fluid, the pumping pressure of the fracturing fluid at a perforating position and the depth of the perforating position.
Wherein the horizontal minimum principal stress and thickness of each formation may be obtained from well logging information. For example, by differential strain in a room experiment, acoustic emission experiments, or calculation of ground stress based on logging information. The depth of the middle position of the fracture can be determined by the fracture constructor through logging information. The fracturing fluid density, the perforation position fracturing fluid pumping pressure and the perforation position depth can be directly obtained in the fracturing construction. The original seam height of the fracture can be calculated by the mode of line elastic fracture mechanics, which is described in the related technology, namely the seam height of the uncorrected fracture. Therefore, for the seam height determination provided in the embodiments of the present disclosure, the original seam height of the fracture belongs to the known value that can be obtained, and the specific calculation method is not described herein.
Step 102: a formation model is created, including a plurality of formations.
Step 103: the stratigraphic model is divided into a plurality of grids.
Step 104: and correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture to each grid.
Step 105: and calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pumping pressure and the perforation position depth.
Step 106: and calculating to obtain the tip stress intensity factor value of the fracture according to the original fracture height and the fluid net pressure of each grid.
Step 107: and correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture.
Step 108: and determining a relation curve according to the corresponding relation between the correction joint height and the pressure of the fracturing fluid pumped into the perforation position.
Step 109: and obtaining the construction pump pressure, and determining the actual seam height of the crack corresponding to the construction pump pressure according to the relation curve.
When the seam height of the fracturing seam is determined by the seam height determining method of the fracturing seam provided by the embodiment of the disclosure, firstly, the horizontal minimum main stress of each stratum, the thickness of each stratum, the depth of the middle position of the fracturing seam, the original seam height of the fracturing seam, the density of fracturing fluid, the pumping pressure of the fracturing fluid at the perforating position and the depth of the perforating position are obtained to provide a data base for the subsequent steps. And then, establishing a stratum model, dividing the stratum model into a plurality of grids, and correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid. This may provide a model basis for subsequent steps. And then, calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pump pressure and the perforation position depth, and calculating to obtain the tip stress intensity factor value of the fracturing crack according to the original joint height and the fluid net pressure of each grid. This can provide a data basis for subsequent corrections to the original seam height. And then, correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture. The corrected seam height is the seam height of the crack obtained after the original seam height is corrected. And determining a relation curve according to the corresponding relation between the correction joint height and the pressure of the fracturing fluid pumped into the perforation position. And finally, acquiring the construction pump pressure, and determining the actual joint height of the crack corresponding to the construction pump pressure according to the relation curve.
That is, according to the method for determining the seam height of the fracturing seam provided by the embodiment of the disclosure, the original seam height is corrected through the tip stress intensity factor value, so that the accuracy of the relationship curve between the corrected seam height and the perforation position fracturing fluid pumping pressure obtained later is high, and then after the construction pumping pressure is known, the accurate actual seam height of the fracturing seam can be obtained according to the relationship curve.
Because the seam height determining method for the fracture seam provided by the embodiment of the disclosure can determine the seam height with higher accuracy, the following two problems can be avoided:
1. the problem that the generated pressure cracks penetrate through the interlayer or shield the stratum from extending due to the fact that the determined seam height is smaller than the actual seam height to blindly increase the pumping discharge capacity can be avoided, so that unnecessary production accidents are avoided, and the construction cost is reduced.
2. The problem that the generated seam height cannot meet the expected design requirement due to the fact that the determined seam height is larger than the actual seam height and the pumping discharge capacity is blindly reduced can be avoided, so that poor fracturing effect and even fracturing failure are avoided.
Fig. 2 is a flowchart of another method for determining a seam height of a fracture according to an embodiment of the present disclosure, and in combination with fig. 2, the method for determining a seam height includes:
step 201: the method comprises the steps of obtaining the horizontal minimum principal stress of each stratum, the thickness of each stratum, the depth of the middle position of a fracture, the original fracture height of the fracture, the density of fracturing fluid, the pumping pressure of the fracturing fluid at a perforating position and the depth of the perforating position.
Step 202: a formation model is created, including a plurality of formations.
In the implementation manner, since the fracture may extend through a plurality of different strata during the extending process, the fracture extension can be conveniently simulated by including a plurality of strata when building the stratum model.
For example, 6 strata are included in the strata model. Of course, the number of formations may be selected based on actual needs, which is not limiting of the present disclosure.
Step 203: the stratigraphic model is divided into a plurality of grids.
Alternatively, step 203 may be implemented by:
first, a perforation location is determined based on the perforation location depth.
Then, a unidirectional number of grids is determined, the unidirectional number being the number of grids required to be divided between the perforation location and the top boundary of the formation model, or between the perforation location and the bottom boundary of the formation model.
It is easy to understand that the greater the number of unidirectional directions, the greater the calculation accuracy in the subsequent steps, but the longer the corresponding calculation time will be. Therefore, a more moderate number of unidirectional numbers needs to be selected. For example, the unidirectional number may be set to 400 to 600, which ensures the calculation accuracy without consuming excessive calculation time. For example, in the present embodiment, the unidirectional number is set to 500.
Finally, according to the unidirectional quantity, dividing the area between the perforation position and the top boundary of the stratum model and the area between the perforation position and the bottom boundary of the stratum model into a plurality of grids respectively by taking the perforation position as a reference.
In the implementation manner, the perforation position is taken as a reference, and the stratum model is divided into a plurality of grids, so that the positioning and the calculation in the subsequent steps can be facilitated, and the accuracy of the seam height determining method is ensured.
Step 204: and correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture to each grid.
In this way, a basis is provided for the subsequent calculation steps.
Step 205: and calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pumping pressure and the perforation position depth.
In this embodiment, the net fluid pressure satisfies the following equation:
wherein p is net (x) Is the net pressure of the fluid, ρ is the density of the fracturing fluid, g is the gravitational acceleration, p ref Pumping pressure of fracturing fluid into perforation position, d mid Depth d of middle position of crack ref In order to achieve the depth of the perforation location,is the horizontal minimum principal stress of the ith formation.
In the above step, the net fluid pressure may be calculated by matlab software based on fracture mechanics.
Step 206: and calculating to obtain the tip stress intensity factor value of the fracture according to the original fracture height and the fluid net pressure of each grid.
In this embodiment, the tip stress intensity factor value satisfies the following formula:
wherein K is I The value of the stress intensity factor of the tip is C which is half value of the original seam height, p net (x) The net pressure of the fluid, d is the differential sign.
In the above implementation, the half value of the original stitch height is half of the original stitch height. The calculation in step 206 is performed by adding up and summing, i.e. the stress intensity factor values of the top boundary and the bottom boundary of the i-th layer are calculated first, and the difference is made to obtain the stress intensity factor value of the tip of the i-th layer. Then, based on this, the i+1th and i-1 th layer tip stress intensity factor values are calculated, the i+2th and i-2 th layer tip stress intensity factor values are calculated, and so on. And finally, accumulating the corresponding tip stress intensity factor values of all the layers, namely obtaining the total tip stress intensity factor value of the fracture in the multi-stratum extension process.
Step 207: and correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture.
Alternatively, step 207 may be implemented by:
first, the formation in which the tip of the fracture is located is determined based on the tip stress intensity factor value.
For example, the tip stress intensity factor value of the fracture may be compared to the fracture toughness of the formation rock. If the tip stress intensity factor value is not greater than the fracture toughness, it indicates that the tip stress intensity factor value of the fracture is insufficient to allow the fracture to continue to extend and propagate. Otherwise, if the tip stress intensity factor value is greater than the fracture toughness, the tip stress intensity factor value representing the fracture will cause the fracture to continue to extend and expand, i.e., into other formations. Then, in the calculating step, the corresponding parameters need to be adjusted to the parameters corresponding to the stratum, so as to improve the accuracy of determining the seam height. The specific stratum where the tip of the fracture is located can be visually seen according to the fracture height curve shown in matlab software.
Alternatively, fracture toughness may be obtained in step 201, in the form of coring the formation for testing.
Then, an upper correction value and a lower correction value of the fracture are determined according to the tip stress intensity factor value and the horizontal minimum principal stress of the stratum where the tip of the fracture is located.
In the present embodiment, the upper correction value and the lower correction value satisfy the following formulas:
wherein e d E is the lower correction value u For the upper correction value, K I+ Is the stress intensity factor value, K of the tip at the lower side of the fracture I- To obtain the stress intensity factor value of the upper tip of the crack,is the horizontal minimum principal stress of the ith formation.
The lower tip stress intensity factor value of the fracture and the upper tip stress intensity factor value of the fracture are both intermediate values calculated when the original fracture height of the fracture is calculated, and therefore are also known values which can be obtained.
And finally, correcting the original seam height according to the upper correction value and the lower correction value to determine the corrected seam height of the crack.
In this embodiment, the correction slit height satisfies the following formula:
A＝2C+e d +e u ； (5)
wherein A is the correction seam height, C is the half value of the original seam height, e d E is the lower correction value u Is the upper correction value.
Fig. 3 is a graph of a seam height correction physical model of the fracture, see fig. 3. Wherein C is half value of original seam height; b is a half value of the correction seam height; p is p net (x) The net pressure of the fluid at any point in the fracture; h is a i I=1, 2, …, n, the thickness of the i-th formation; sigma (sigma) i I=1, 2, …, n, the horizontal minimum principal stress of the i-th formation; k (K) ICi For fracture toughness of the i-th formation rock, i=1, 2, …, n; h is a i I=1, 2, …, n for the i-th layer thickness; tipu1 and tipu2 are the upper tip positions of the fracture when the influence of the shaping region is not considered and when the influence of the shaping region is considered, respectively; tipd1 and tipd2 are respectively when the influence of the shaping region is not consideredAnd considering the lower tip position of the fracture when the shaping area is affected; k (K) I1- And K I2- The upper tip stress intensity factor values of the fracture when the influence of the shaping area is not considered and when the influence of the shaping area is considered are respectively given; k (K) I1+ And K I2+ The stress intensity factor values of the tip of the lower side of the crack when the influence of the crack shaping area is not considered and when the influence of the crack shaping area is considered are respectively given; d, d ref And d mid The depth of the perforation position and the depth of the middle position of the fracture are respectively; p is p ref And p mid Perforation location pressure and mid-location pressure of the fracture, respectively.
Step 208: and determining a relation curve according to the corresponding relation between the correction joint height and the pressure of the fracturing fluid pumped into the perforation position.
In the above implementation, steps 205-207 are repeated to obtain multiple sets of corresponding corrected slot heights and perforating position fracturing fluid pumping pressures, thereby plotting a relationship graph (see fig. 4).
As can be seen from fig. 4, in this embodiment, 6 formations (i.e., different formations separated by a transverse dashed line) are modeled, and in this range, a graph of the correspondence between the corrected fracture height and the perforating position fracturing fluid pumping pressure is plotted.
The construction pump pressure refers to the pressure output by the pump at the surface wellhead, can be directly obtained in fracturing construction, and belongs to the known value which can be obtained. This pressure is different from the pressure at which the fracturing fluid is pumped in from the surface wellhead to the perforation location, as the fracturing fluid is lost during its flow from the surface wellhead to the perforation location. Therefore, when the relation curve is referred to later, the perforating position fracturing fluid pumping pressure corresponding to the construction pumping pressure needs to be calculated.
Step 209: and calculating to obtain the corresponding perforation position fracturing fluid pumping pressure according to the construction pumping pressure.
In this embodiment, the perforating position fracturing fluid pumping pressure satisfies the following equation:
P pump ＝P n -ΔP h +ΔP c +ΔP t ； (6)
wherein P is pump To construct the pump pressure, P n Pumping pressure, delta P, of fracturing fluid into perforation positions h Is hydrostatic column pressure, deltaP c For the loss pressure of the nozzle, deltaP t Pressure is lost for the string.
Step 210: and determining the actual seam height of the fracturing fluid at the perforation position corresponding to the construction pump pressure according to the perforation position corresponding to the construction pump pressure by referring to the relation curve.
In the implementation manner, the perforation position fracturing fluid pumping pressure corresponding to the construction pumping pressure is compared with the relation graph, the same perforation position fracturing fluid pumping pressure in the relation graph is found out, the corresponding correction seam height is determined as the actual seam height corresponding to the construction pumping pressure.
It should be noted that, as shown in the foregoing description, the formation model provided in this embodiment includes 6 layers of formations, and if the upper side or the lower side of the fracture is found to exceed the range of 500 grids in the comparison graph, it indicates that the formation model needs to be expanded to meet the requirement.
That is, the seam height determining method provided by the embodiment of the disclosure can overcome the defect that the conventional seam height calculation model cannot consider that the seam height of the seam extends in shale strata with different multilayer attributes, and enables the seam height determining result to be more real and reliable.
And determining the actual seam height of the fracturing fluid at the perforation position corresponding to the construction pump pressure according to the perforation position corresponding to the construction pump pressure by referring to the relation curve.
When the seam height of the fracturing seam is determined by the seam height determining method of the fracturing seam provided by the embodiment of the disclosure, firstly, the horizontal minimum main stress of each stratum, the thickness of each stratum, the depth of the middle position of the fracturing seam, the original seam height of the fracturing seam, the density of fracturing fluid, the pumping pressure of the fracturing fluid at the perforating position and the depth of the perforating position are obtained to provide a data base for the subsequent steps. And then, establishing a stratum model, dividing the stratum model into a plurality of grids, and correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid. This may provide a model basis for subsequent steps. And then, calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pump pressure and the perforation position depth, and calculating to obtain the tip stress intensity factor value of the fracturing crack according to the original joint height and the fluid net pressure of each grid. This can provide a data basis for subsequent corrections to the original seam height. And then, correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the fracture. The corrected seam height is the seam height of the crack obtained after the original seam height is corrected. And determining a relation curve according to the corresponding relation between the correction joint height and the pressure of the fracturing fluid pumped into the perforation position. And finally, acquiring the construction pump pressure, and determining the actual joint height of the crack corresponding to the construction pump pressure according to the relation curve.
That is, according to the method for determining the seam height of the fracturing seam provided by the embodiment of the disclosure, the original seam height is corrected through the tip stress intensity factor value, so that the accuracy of the relationship curve between the corrected seam height and the perforation position fracturing fluid pumping pressure obtained later is high, and then after the construction pumping pressure is known, the accurate actual seam height of the fracturing seam can be obtained according to the relationship curve.
The foregoing description of the preferred embodiments of the present disclosure is provided for the purpose of illustration only, and is not intended to limit the disclosure to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, alternatives, and alternatives falling within the spirit and principles of the disclosure.
Claims (10)
1. A seam height determination method for a fracture, the method being adapted to a computer, the seam height determination method comprising:
obtaining the horizontal minimum principal stress of each stratum, the thickness of each stratum, the depth of the middle position of a fracture, the original fracture height of the fracture, the density of fracturing fluid, the pumping pressure of the fracturing fluid at a perforating position and the depth of the perforating position;
establishing a stratum model, wherein the stratum model comprises a plurality of stratum;
dividing the stratigraphic model into a plurality of grids;
correspondingly assigning the horizontal minimum principal stress of each stratum, the thickness of each stratum and the depth of the middle position of the fracture into each grid;
calculating to obtain the fluid net pressure of each grid based on the fracturing fluid density, the perforation position fracturing fluid pump pressure and the perforation position depth;
calculating to obtain a tip stress intensity factor value of the fracture according to the original joint height and the fluid net pressure of each grid;
correcting the original seam height according to the tip stress intensity factor value to determine the corrected seam height of the crack;
determining a relation curve according to the corresponding relation between the correction joint height and the perforation position fracturing fluid pump pressure;
and acquiring construction pump entry pressure, and determining the actual seam height of the crack corresponding to the construction pump entry pressure according to the relation curve.
2. The seam height determination method of claim 1, wherein the dividing the formation model into a plurality of grids comprises:
determining a perforation position according to the perforation position depth;
determining a unidirectional number of the grids, wherein the unidirectional number is the number of the grids required to be divided between the perforation positions and the top boundary of the stratum model or between the perforation positions and the bottom boundary of the stratum model;
and dividing the area between the perforation position and the top boundary of the stratum model and the area between the perforation position and the bottom boundary of the stratum model into a plurality of grids respectively according to the unidirectional quantity and taking the perforation position as a reference.
3. The seam height determination method according to claim 2, wherein the unidirectional number is set to 400 to 600.
4. The seam height determination method of claim 1, wherein the net fluid pressure satisfies the following equation:
p net (x)＝ρgx+p ref +10 -6 m(d mid -d ref )-σ h,i ；
wherein p is net (x) For the net fluid pressure, ρ is the fracturing fluid density, g is the gravitational acceleration, p ref Pumping fracturing fluid into the perforation position, d mid D is the depth of the middle position of the crack ref For the depth of the perforation location, sigma h,i The horizontal minimum principal stress of the formation is the i-th layer.
5. The stitch height determination method as recited in claim 1, wherein the tip stress intensity factor value satisfies the following equation:
wherein K is I For the tip stress intensity factor value, C is the half value of the original stitch height, p net (x) D is a differential sign for the net pressure of the fluid.
6. The seam height determination method of claim 1, wherein the correcting the original seam height based on the tip stress intensity factor value to determine a corrected seam height of the fracture comprises:
determining the stratum where the tip of the fracture is located according to the tip stress intensity factor value;
determining an upper correction value and a lower correction value of the fracture according to the tip stress intensity factor value and the horizontal minimum principal stress of the stratum where the tip of the fracture is located;
and correcting the original seam height according to the upper correction value and the lower correction value to determine the corrected seam height of the crack.
7. The slot height determination method according to claim 6, wherein the upper side correction value and the lower side correction value satisfy the following formula:
wherein e d For the lower correction value e u For the upper correction value, K I+ For the stress intensity factor value, K, of the lower tip of the fracture I- For the upper tip stress intensity factor value, sigma, of the crack h,i The horizontal minimum principal stress of the formation is the i-th layer.
8. The seam height determination method of claim 7, wherein the corrected seam height satisfies the following formula:
A＝2C+e d +e u ；
wherein A is the corrected slot height, C is the half value of the original slot height, e d For the lower correction value e u For the upper correction value.
9. The method for determining the seam height according to claim 1, wherein the step of obtaining the construction pump entry pressure and determining the actual seam height of the fracture corresponding to the construction pump entry pressure according to the relation curve includes:
calculating to obtain the corresponding perforation position fracturing fluid pumping pressure according to the construction pumping pressure;
and determining the actual seam height of the fracturing fluid at the perforation position corresponding to the construction pump pressure according to the construction pump pressure and referring to the relation curve.
10. The fracture height determination method of claim 1, wherein the perforating location frac fluid pumping pressure satisfies the following equation:
P pump ＝P n -ΔP h +ΔP c +ΔP t ；
wherein P is pump For the construction pump to pump in pressure, P n Pumping pressure, delta P, of fracturing fluid into the perforation location h Is hydrostatic column pressure, deltaP c For the loss pressure of the nozzle, deltaP t Pressure is lost for the string.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010854615.6A CN114086946B (en) | 2020-08-24 | 2020-08-24 | Crack height determining method for crack |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010854615.6A CN114086946B (en) | 2020-08-24 | 2020-08-24 | Crack height determining method for crack |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114086946A CN114086946A (en) | 2022-02-25 |
| CN114086946B true CN114086946B (en) | 2023-08-22 |
Family
ID=80295299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010854615.6A Active CN114086946B (en) | 2020-08-24 | 2020-08-24 | Crack height determining method for crack |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114086946B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4850431A (en) * | 1988-05-06 | 1989-07-25 | Halliburton Company | Method of forming a plurality of spaced substantially parallel fractures from a deviated well bore |
| CN102518417A (en) * | 2011-12-16 | 2012-06-27 | 中国石油大学(北京) | Method for determining output volume of hydrofracture of shale gas reservoir |
| CN103256046A (en) * | 2013-04-28 | 2013-08-21 | 北京大学 | Unconventional oil and gas reservoir horizontal well section full-fracture-length fracturing parameter analog method and device |
| CN103670358A (en) * | 2013-11-25 | 2014-03-26 | 北京科技大学 | Fracture extension judging method of hydraulic fracturing crack on sand shale thin interbed geological interface |
| CN106844909A (en) * | 2017-01-05 | 2017-06-13 | 西南石油大学 | A kind of computational methods of compact reservoir fracturing reform volume area |
| CN108280275A (en) * | 2018-01-09 | 2018-07-13 | 中国石油大学(华东) | A kind of high prediction technique of tight sand hydraulic fracturing seam |
| CN108829994A (en) * | 2018-06-23 | 2018-11-16 | 东北石油大学 | Multilayer shale pseudo-three-dimensional fracture modeling stitches high method for solving |
| CN108868748A (en) * | 2018-04-28 | 2018-11-23 | 中国石油化工股份有限公司江汉油田分公司石油工程技术研究院 | A kind of calculation method of shale gas horizontal well refracturing crack cracking pressure |
| CN109577958A (en) * | 2018-11-02 | 2019-04-05 | 中国石油天然气股份有限公司 | A kind of method of pulsed neutron log time spectrum evaluation tracer ceramic fracturing slit width |
| CN111197476A (en) * | 2020-01-08 | 2020-05-26 | 西南石油大学 | Acid fracturing fracture body etching form calculation method considering complex fluid loss medium |
| US10689972B1 (en) * | 2019-05-31 | 2020-06-23 | Southwest Petroleum University | Automatic diagnosis method for wellhead pressure curve of hydraulic fracturing in shale gas horizontal well |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RS64824B1 (en) * | 2014-06-05 | 2023-12-29 | Geoquest Systems Bv | Method for improved design of hydraulic fracture height in a subterranean laminated rock formation |
| CA3020545A1 (en) * | 2017-10-13 | 2019-04-13 | Uti Limited Partnership | Completions for inducing fracture network complexity |
-
2020
- 2020-08-24 CN CN202010854615.6A patent/CN114086946B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4850431A (en) * | 1988-05-06 | 1989-07-25 | Halliburton Company | Method of forming a plurality of spaced substantially parallel fractures from a deviated well bore |
| CN102518417A (en) * | 2011-12-16 | 2012-06-27 | 中国石油大学(北京) | Method for determining output volume of hydrofracture of shale gas reservoir |
| CN103256046A (en) * | 2013-04-28 | 2013-08-21 | 北京大学 | Unconventional oil and gas reservoir horizontal well section full-fracture-length fracturing parameter analog method and device |
| CN103670358A (en) * | 2013-11-25 | 2014-03-26 | 北京科技大学 | Fracture extension judging method of hydraulic fracturing crack on sand shale thin interbed geological interface |
| CN106844909A (en) * | 2017-01-05 | 2017-06-13 | 西南石油大学 | A kind of computational methods of compact reservoir fracturing reform volume area |
| CN108280275A (en) * | 2018-01-09 | 2018-07-13 | 中国石油大学(华东) | A kind of high prediction technique of tight sand hydraulic fracturing seam |
| CN108868748A (en) * | 2018-04-28 | 2018-11-23 | 中国石油化工股份有限公司江汉油田分公司石油工程技术研究院 | A kind of calculation method of shale gas horizontal well refracturing crack cracking pressure |
| CN108829994A (en) * | 2018-06-23 | 2018-11-16 | 东北石油大学 | Multilayer shale pseudo-three-dimensional fracture modeling stitches high method for solving |
| CN109577958A (en) * | 2018-11-02 | 2019-04-05 | 中国石油天然气股份有限公司 | A kind of method of pulsed neutron log time spectrum evaluation tracer ceramic fracturing slit width |
| US10689972B1 (en) * | 2019-05-31 | 2020-06-23 | Southwest Petroleum University | Automatic diagnosis method for wellhead pressure curve of hydraulic fracturing in shale gas horizontal well |
| CN111197476A (en) * | 2020-01-08 | 2020-05-26 | 西南石油大学 | Acid fracturing fracture body etching form calculation method considering complex fluid loss medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114086946A (en) | 2022-02-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108868748B (en) | Method for calculating repeated fracturing fracture opening pressure of shale gas horizontal well | |
| Can et al. | Simple tools for forecasting waterflood performance | |
| CN110469303B (en) | Volume fracturing parameter optimization design method based on four types of transformation volumes | |
| CN108843313A (en) | Shale formation drilling safety drilling fluid density window design method | |
| CN113076676B (en) | Unconventional oil and gas reservoir horizontal well fracture network expansion and production dynamic coupling method | |
| CN105893679A (en) | Afterflow correction well test interpretation method of low-production horizontal well | |
| CN114086946B (en) | Crack height determining method for crack | |
| CN109630088A (en) | A kind of determination method of High Position Drilling position | |
| CN111456709B (en) | Horizontal well multistage fracturing segmentation clustering method based on logging curve | |
| CN107575219A (en) | A kind of shale gas reservoir formation fracture pressure gradient computational methods | |
| CN114239308B (en) | Multi-scale high-density fracturing parameter optimization method | |
| CN109446602A (en) | A kind of Numerical Experimental Method of surface vertical borehole extraction super high seam gas | |
| CN113027529B (en) | Stope impact risk assessment method based on numerical inversion | |
| CN108829994B (en) | Multilayer shale simulated three-dimensional fracturing model seam height solving method | |
| CN107339096A (en) | A kind of quick groundwater prospecting method of horizontal well | |
| CN113591421B (en) | Heterogeneous reservoir horizontal well sand liquid production profile dynamic evolution simulation and prediction method | |
| CN111680814B (en) | Elastic-driving reasonable production allocation optimization method for fractured-vuggy carbonate reservoir | |
| CN114757029A (en) | Method and system for simulating multi-stage emission reduction filling construction of alpha-beta wave of offshore long horizontal well | |
| CN110067555A (en) | The determination method and apparatus of the minimum dynamic holdup of carbonate rock oil well | |
| CN111898177B (en) | Calculation method of stratified foundation consolidation degree | |
| CN112861068A (en) | Method for determining mining overburden rock damage height | |
| CN115270533A (en) | Repeated fracturing design method and device, storage medium and electronic equipment | |
| CN111563307B (en) | Working parameter configuration method and device of gas injection equipment | |
| CN112267872B (en) | Method for determining volume of gas well drilling karst cave system by using production dynamic data | |
| CN114033356B (en) | Coal measure stratum ground stress calculation method and device |
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 |