A method and system for designing the permeability of chemical sand consolidation layers in gas reservoirs

Abstract

The present invention provides a method and system for determining the permeability of a chemical sand consolidation layer in a gas reservoir. The method solves a planar radial flow model in a permeability mutation formation according to the formation productivity retention rate and the assignment method, determines the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and then determines the designed permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius and in combination with the sand consolidation radius designed for chemical sand consolidation. The determined permeability is used to guide the evaluation and construction of the chemical sand consolidation process, ensuring that the sand consolidation layer can maintain a reasonable permeability while meeting the sand control requirements, balancing the relationship between sand control and productivity, and ensuring the effectiveness of the subsequent implementation of chemical sand consolidation measures.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploitation, and in particular to a method and system for designing the permeability of a chemical sand consolidation layer in a gas reservoir. Background Art

[0002] Chemical sand control refers to a sand control technology that involves injecting chemical sand-fixing agents into the formation from the ground through cement trucks to cement and solidify the loose sandstone in the formation, forming a stable barrier with a certain permeability to increase the strength of the oil layer and thereby prevent sand from coming out of the formation.

[0003] Since the permeability of consolidated formations generally decreases, which can have a certain impact on oil and gas well productivity, there is currently a lack of research on how to determine a reasonable permeability of the sand consolidation layer to ensure the productivity of oil and gas wells after sand consolidation. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a method and system for determining the permeability of the chemical sand consolidation layer of a gas reservoir, ensuring that the sand consolidation layer can maintain a reasonable permeability while meeting the sand control requirements, guiding the evaluation and construction of the chemical sand consolidation process, and scientifically balancing the relationship between sand control and production capacity.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for designing the permeability of a chemical sand consolidation layer in a gas reservoir comprises the following steps:

[0007] Step 1: Construct a plane radial flow model before sand consolidation based on reservoir and fluid data;

[0008] Step 2: Conduct a seepage simulation of the plane radial flow model before sand consolidation to determine the formation productivity before sand consolidation;

[0009] Step 3: Based on the reservoir data, fluid data, sand consolidation layer permeability and sand consolidation radius, a plane radial flow model in the permeability mutation formation is established;

[0010] Step 4: Using the assignment method and combining the formation productivity retention rate, solve the plane radial flow model in the permeability mutation formation to determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius;

[0011] Step 5: Determine the designed permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius and the sand consolidation radius designed for chemical sand consolidation.

[0012] Preferably, the reservoir and fluid data include reservoir permeability K, reservoir opening thickness h, reservoir pressure p e , reservoir temperature T, bottom hole pressure p wf , fluid viscosity u, deviation coefficient Z and supply radius re .

[0013] Preferably, the formation productivity before sand consolidation is expressed as follows:

[0014]

[0015] Where q is the formation productivity; K is the reservoir well test permeability; h is the reservoir opening thickness; p e is the reservoir pressure; p wf is the bottom hole pressure; T is the reservoir temperature; u is the fluid viscosity; Z is the deviation coefficient; r e is the supply radius; r w is the wellbore radius.

[0016] Preferably, the relationship between the permeability of the sand consolidation layer and the sand consolidation radius is as follows:

[0017]

[0018] Where a is the formation productivity retention rate; k a is the permeability of the sand consolidation layer; r a is the designed radius of the sand consolidation layer.

[0019] Preferably, the assignment method in step 4 is to give a preset value to the permeability or radius of the sand consolidation layer, and then solve the plane radial flow model of the permeability mutation formation.

[0020] A system for designing a method for permeability of a chemical sand consolidation layer in a gas reservoir, comprising:

[0021] Model building module, used to build a plane radial flow model before sand consolidation based on reservoir and fluid data;

[0022] The formation productivity module is used to determine the formation productivity before sand consolidation based on the plane radial flow model before sand consolidation;

[0023] The mutation model building module builds a plane radial flow model for permeability mutation formations based on reservoir and fluid data, sand consolidation layer permeability, and sand consolidation radius;

[0024] The solution module is used to solve the plane radial flow model in the permeability mutation formation by using assignment, and determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius;

[0025] The permeability module is used to determine the design permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and combined with the sand consolidation radius of the chemical sand consolidation design.

[0026] A terminal system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for designing the permeability of a chemical sand consolidation layer in a gas reservoir are implemented.

[0027] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for designing the permeability of a chemical sand consolidation layer in a gas reservoir.

[0028] Compared with the prior art, the present invention has the following beneficial technical effects:

[0029] The present invention provides a method for determining the permeability of a chemical sand consolidation layer in a gas reservoir. The method solves a planar radial flow model in a permeability mutation formation according to the formation productivity retention rate and the assignment method, determines the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and then determines the designed permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius and in combination with the sand consolidation radius designed for chemical sand consolidation. The determined permeability is used to guide the evaluation and construction of the chemical sand consolidation process, ensuring that the sand consolidation layer can maintain a reasonable permeability while meeting the sand control requirements, balancing the relationship between sand control and productivity, and ensuring the effectiveness of the subsequent implementation of chemical sand consolidation measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The plane radial flow model of the present invention in the formation with the same permeability;

[0031] Figure 2 This is the plane radial flow model of the permeability mutation formation of the present invention;

[0032] Figure 3 This is a curve diagram showing the relationship between the permeability of the sand consolidation layer and the sand consolidation radius of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings, which are intended to explain rather than limit the present invention.

[0034] See Figure 1 and 2 A method for designing the permeability of a chemical sand consolidation layer in a gas reservoir comprises the following steps:

[0035] Step 1: Construct a plane radial flow model based on reservoir and fluid data.

[0036] Reservoir and fluid data include reservoir permeability K, reservoir opening thickness h, reservoir pressure p e , reservoir temperature T, bottom hole pressure p wf , fluid viscosity u, deviation coefficient Z and supply radius r e .

[0037] S1. Obtain reservoir permeability K.

[0038] In order to comprehensively reflect the actual flow capacity of the fluid in the reservoir, the permeability value obtained from the well test interpretation is selected.

[0039] S2. Obtain the reservoir opening thickness h.

[0040] For open hole or screen completion, the reservoir opening thickness is the thickness of the reservoir section uncovered by drilling; for cased perforation completion, the reservoir opening thickness is the total length of the perforated section.

[0041] S3. Obtain reservoir pressure pe and reservoir temperature T.

[0042] Through downhole pressure testing, the pressure gauge is lowered into the vicinity of the production layer, and the well is shut down until the pressure returns to stability. The pressure measured at this time is the formation pressure, and the reservoir temperature is also recorded.

[0043] S4. Obtain the bottom hole flowing pressure pwf.

[0044] During the gas well production process, through downhole pressure testing, a pressure gauge is lowered into the vicinity of the production layer. The pressure measured at this time is the bottomhole flowing pressure.

[0045] S5. Obtain the fluid viscosity u.

[0046] The production fluid is sampled and the fluid viscosity is obtained through experimental testing.

[0047] S6. Obtain the deviation coefficient Z.

[0048] Obtained by looking up the chart or calculating after defining the fluid components in the pipesim software.

[0049] S7. Confirm the supply radius re.

[0050] Select half of the distance between two adjacent wells.

[0051] Step 2: Perform seepage simulation of the plane radial flow model before sand consolidation to determine the formation productivity before sand consolidation; the expression of the formation productivity is as follows:

[0052]

[0053] In formula 1: q is the gas production under standard conditions, m 3 / d; K is the reservoir well test permeability, mD; h is the reservoir opening thickness, m; p e is the reservoir pressure, MPa; p wf is the bottom hole pressure, MPa; T is the reservoir temperature, K; u is the fluid viscosity, mPa.s; Z is the deviation coefficient; r e is the supply radius, m; r wis the wellbore radius, m.

[0054] Plane radial flow, also known as radial flow, refers to a flow pattern in which streamlines are straight and converge toward or diverge from a central wellpoint in two dimensions. In homogeneous, isotropic formations, due to their symmetry, studying the flow pattern in one radial direction (one streamline) can represent the flow patterns along all other streamlines. This type of flow is considered one-dimensional.

[0055] Step 3: Based on the reservoir and fluid data, as well as the permeability and radius of the sand consolidation layer, a plane radial flow model in the permeability mutation formation is established;

[0056] Step 4: Using the assignment method combined with the oil field's formation productivity retention rate, solve the plane radial flow model in the permeability mutation formation to determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius;

[0057]

[0058] In formula 2: a is the formation productivity retention rate, %; k a is the permeability of the sand consolidation layer; r a is the designed radius of the sand consolidation layer.

[0059] Step 5: Establish a relationship chart based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and determine the design permeability of the sand consolidation layer in combination with the sand consolidation radius designed for chemical sand consolidation.

[0060] The present invention also provides a system for designing the permeability of a chemical sand consolidation layer in a gas reservoir, comprising:

[0061] The formation productivity module is used to determine the formation productivity before sand consolidation based on the plane radial flow model before sand consolidation;

[0062] The mutation model building module builds a plane radial flow model for permeability mutation formations based on reservoir and fluid data, sand consolidation layer permeability, and sand consolidation radius;

[0063] The solution module is used to solve the plane radial flow model in the permeability mutation formation by using assignment, and determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius;

[0064] The permeability module is used to determine the design permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and combined with the sand consolidation radius of the chemical sand consolidation design.

[0065] Example 1

[0066] Taking the XX gas well in Tarim Oilfield as an example, the comprehensive permeability of the reservoir is 40mD, the reservoir opening thickness is 155m, the formation pressure is 95.57MPa, the bottom hole pressure is 95.44MPa, the fluid viscosity is 0.04242mPa.s, the supply radius is 548m, the wellbore radius is 0.0841m, the viscosity is 0.04242mPa.s, the deviation coefficient is 1.666, and the reservoir temperature is 170℃.

[0067] First, the daily gas production of this well before sand consolidation is calculated by formula 1 to be 548,000 cubic meters / day, assuming that the oil field requires a production capacity retention rate of 80%.

[0068] Then, by using the relationship between the permeability of the sand consolidation layer and the sand consolidation radius 2, the sand consolidation radius value is changed to obtain the curve of the permeability of the sand consolidation layer. Figure 3 .

[0069] Finally, assuming that the radius of the sand consolidation layer of the well is 3m, then according to Figure 3 It was found that the permeability requirement of the sand consolidation layer is 25mD.

[0070] In an exemplary embodiment, a computer-readable storage medium is also provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method for determining the permeability of a chemically consolidated sand layer in a gas reservoir. The computer storage medium can be any available medium or data storage device accessible by a computer, including but not limited to magnetic storage (e.g., floppy disks, hard disks, magnetic tapes, magneto-optical disks (MOs), etc.), optical storage (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (e.g., ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid-state drives (SSDs), etc.).

[0071] In an exemplary embodiment, a correction terminal system is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for determining the permeability of a chemically consolidated sand layer in a gas reservoir are implemented. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0072] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for designing the permeability of a chemical sand consolidation layer in a gas reservoir, characterized in that: The following steps are involved: Step 1: Construct a plane radial flow model before sand consolidation based on reservoir and fluid data; Step 2: Conduct a seepage simulation of the plane radial flow model before sand consolidation to determine the formation productivity before sand consolidation; Step 3: Based on the reservoir data, fluid data, sand consolidation layer permeability and sand consolidation radius, a plane radial flow model in the permeability mutation formation is established; Step 4: Using the assignment method and combining the formation productivity retention rate, solve the plane radial flow model in the permeability mutation formation to determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius; Step 5: Determine the designed permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius and the sand consolidation radius designed for chemical sand consolidation.

2. The method for designing the permeability of a chemical sand consolidation layer in a gas reservoir according to claim 1, characterized in that: The reservoir and fluid data include reservoir permeability K, reservoir opening thickness h, reservoir pressure p e , reservoir temperature T, bottom hole pressure p wf , fluid viscosity u, deviation coefficient Z and supply radius r e .

3. The method for designing the permeability of a chemical sand consolidation layer in a gas reservoir according to claim 1, characterized in that: The formation productivity expression before sand consolidation is as follows: Where q is the formation productivity; K is the reservoir well test permeability; h is the reservoir opening thickness; p e is the reservoir pressure; p wf is the bottom hole pressure; T is the reservoir temperature; u is the fluid viscosity; Z is the deviation coefficient; r e is the supply radius; r w is the wellbore radius.

4. The method for designing the permeability of a chemical sand consolidation layer in a gas reservoir according to claim 1, characterized in that: The relationship between the permeability of the sand consolidation layer and the sand consolidation radius is as follows: Where a is the formation productivity retention rate; k a is the permeability of the sand consolidation layer; r a is the designed radius of the sand consolidation layer.

5. The method for designing the permeability of a chemical sand consolidation layer in a gas reservoir according to claim 1, characterized in that: The assignment method in step 4 is to give a preset value to the permeability or radius of the sand consolidation layer, and then solve the plane radial flow model of the permeability mutation formation.

6. A system for designing the permeability of a chemical sand consolidation layer in a gas reservoir according to any one of claims 1 to 5, characterized in that: include, Model building module, used to build a plane radial flow model before sand consolidation based on reservoir and fluid data; The formation productivity module is used to determine the formation productivity before sand consolidation based on the plane radial flow model before sand consolidation; The mutation model building module builds a plane radial flow model for permeability mutation formations based on reservoir and fluid data, sand consolidation layer permeability, and sand consolidation radius; The solution module is used to solve the plane radial flow model in the permeability mutation formation by using assignment, and determine the relationship between the permeability of the sand consolidation layer and the sand consolidation radius; The permeability module is used to determine the design permeability of the sand consolidation layer based on the relationship between the permeability of the sand consolidation layer and the sand consolidation radius, and combined with the sand consolidation radius of the chemical sand consolidation design.

7. A terminal system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for designing the permeability of the chemical sand consolidation layer in a gas reservoir are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for designing the permeability of a chemical sand consolidation layer in a gas reservoir are implemented.

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