Prediction method for shale gas deployment / drilled horizontal well EUR in different exploration and development stages
By dividing block types and using specific EUR calculation parameters, the roughness and limitations of shale gas well EUR prediction in existing technologies are solved, and rapid and accurate prediction of EUR for deployed and completed wells is achieved, supporting the benefit evaluation of shale gas development.
Patent Information
- Application Number
- CN202410334913.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-22
- Publication Date
- 2025-09-23
AI Technical Summary
Existing technologies have difficulty in effectively predicting the ultimate recoverable reserves (EUR) of shale gas wells at different exploration and development stages, especially in the well deployment and completion stages. The prediction results are rough and limited to blocks with rich production data.
Based on production data from different exploration and development stages, the blocks are divided into different types. Based on the EUR calculation parameters of different block types, a specific formula is used to predict the EUR of deployed/completed horizontal wells, including standard well parameters, contribution of each small layer, high-quality reservoir thickness, etc., to form a more targeted prediction method.
It has achieved rapid and effective prediction of EUR for shale gas wells in different exploration and development stages, evaluated implementation benefits, promoted the progress of block production capacity construction, and ensured the profitable development of shale gas.
Smart Images
Figure CN120688203A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of EUR (ultimate recoverable reserves) prediction of shale gas wells, and in particular to a method for predicting EUR of shale gas deployment / completion horizontal wells at different exploration and development stages. Background Art
[0002] my country possesses abundant shale gas resources, making it a prime target for future natural gas extraction. Currently, the Longmaxi Formation shale gas has entered a period of rapid production, and shale gas development in new blocks and formations is also actively expanding, presenting an extremely promising prospect for exploration and development. Currently, shale gas development typically utilizes long horizontal drilling and hydraulic fracturing, which are associated with high construction costs. To ensure profitable gas well development, a pre-implementation gas well benefit evaluation is necessary. This includes forecasting gas well investment and production capacity during development deployment and well completion, initially clarifying the potential benefits of well implementation, and ultimately evaluating whether the block is profitable.
[0003] Currently, there are many methods used to evaluate the production performance of shale gas wells and the production potential of blocks, including gas production per unit pressure drop, test gas production, gas breakthrough time and shale gas well EUR parameters. Among them, shale gas well EUR is the most commonly used and reliable.
[0004] Currently, there are mainly the following types of EUR prediction methods for shale gas wells: (1) Based on the data of multiple sample gas wells, a mapping relationship between estimated cumulative production and EUR is established, and the EUR of the target gas well is determined by combining the estimated cumulative production of the target gas well and the mapping relationship; (2) By analyzing gas wells that have been in production for more than one year, the analogical relationship between EUR and first-year production and the linear relationship between various factors and first-year production are determined, and then the EUR of shale gas wells that have been in production for less than one year is calculated; (3) Based on the geological, fracturing, testing and production data of a single well, a EUR prediction model is established to predict EUR; (4) Using gas well production data, a characteristic curve is constructed, and combined with gas well flow analysis, the identified boundary flow stage is extrapolated to the economic limit gas production of the gas well, and then the EUR is calculated; (5) By analyzing the implemented wells, different EUR range levels are divided and the corresponding average recovery rate is obtained. After obtaining the well-controlled reserves of the well to be predicted, the estimated EUR of the gas well in different EUR range levels is calculated based on the average recovery rate.
[0005] To cope with the rapid development of shale gas, it is necessary to strengthen the prediction of deployment and well implementation results at different stages and evaluate the benefits of block development. Current EUR prediction methods primarily focus on wells already in production. Only the fifth method can predict the EUR of deployed and completed wells. However, these predictions are relatively crude and are limited to blocks with extensive production data. Therefore, a more comprehensive and targeted EUR prediction method is necessary. Summary of the Invention
[0006] In view of this, based on the different production data of shale gas blocks in different exploration and development stages, the present invention provides a prediction method for EUR of shale gas deployment / completion horizontal wells in different exploration and development stages for deployment wells and completion wells.
[0007] The present invention discloses a method for predicting EUR of shale gas deployment / completion horizontal wells at different exploration and development stages, which includes:
[0008] Production data for the blocks where deployed / completed horizontal wells are located is collected and, based on this data, the block types are classified. EUR calculation parameters corresponding to the different block types are obtained. Based on the obtained EUR calculation parameters corresponding to the different block types, the EUR of the deployed / completed horizontal wells is predicted.
[0009] Furthermore, the production data include the length of the horizontal section of the implemented well, the target drilling rate, EUR data, production logging data, and the thickness of high-quality reservoirs.
[0010] Furthermore, the different block types include type one, type two, type three and type four; type one indicates that there are many producing wells, abundant production data, and a standard well model can be formed; type two indicates that there are few producing wells, less production data, but there are production logging data, and the EUR contribution of each sub-layer can be analyzed; type three indicates that there is no production logging data, but there are producing wells, and high-quality reservoir data and production data can be obtained; type four indicates that there are no producing wells, but there are evaluation well data, and high-quality reservoir data can be obtained.
[0011] Furthermore, the EUR calculation parameters corresponding to different block types are obtained according to different block types, including:
[0012] According to type 1, the EUR calculation parameters obtained include the horizontal section length L of the standard well 标 , target drilling rate Φ 标 , the ultimate recoverable reserves of standard wells EUR 标 ;
[0013] According to type 2, the EUR calculation parameters obtained include the EUR contribution per meter of each small layer in the block;
[0014] According to Type 3, the EUR calculation parameters obtained include the distribution of high-quality reservoir thickness and the high-quality reservoir thickness H of the producing wells. 投 , horizontal section length L 投 , target drilling rate Φ 投 , well spacing S 投 , EUR 投 ;
[0015] According to Type 4, the EUR calculation parameters obtained include the thickness distribution of high-quality reservoirs.
[0016] Furthermore, the EUR of the deployed / drilled horizontal well is predicted based on the obtained EUR calculation parameters corresponding to the different block types, including:
[0017] If the block where the deployed or completed well is located belongs to Type 1, the EUR forecast is carried out as follows:
[0018] EUR 部署 / 完钻 =EUR 标 ×[(L 部署 / 完钻 ×Φ 部署 / 完钻 )÷(L 标 ×Φ 标 )]
[0019] Where, L 标 is the horizontal section length of the standard well, Φ 标 is the target drilling rate of standard wells, EUR 标 For standard well EUR, L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, Φ 部署 / 完钻 is the target drilling rate of the deployed / completed horizontal well to be calculated, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated.
[0020] Furthermore, the EUR of the deployed / drilled horizontal well is predicted based on the obtained EUR calculation parameters corresponding to the different block types, including:
[0021] If the block where the deployed or completed well is located belongs to Type 2, the EUR forecast is carried out as follows:
[0022]
[0023] Where, L xi-部署 / 完钻 EUR is the length of each layer encountered in the horizontal section of the deployed / completed horizontal well to be calculated. xi EUR is the EUR contribution per meter of each layer in the block, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated.
[0024] Furthermore, the EUR of the deployed / drilled horizontal well is predicted based on the obtained EUR calculation parameters corresponding to the different block types, including:
[0025] If the block where the deployed or completed well is located belongs to Type 3 or Type 4, the EUR forecast is carried out as follows:
[0026] EUR 部署 / 完钻 =A×ln(L 部署 / 完钻 ×Φ 部署 / 完钻 ×S 部署 / 完钻 ×H 部署 / 完钻 )-B
[0027] Where, L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, Φ 部署 / 完钻 is the target drilling rate of the deployed / drilled horizontal well to be calculated, S 部署 / 完钻 is the spacing between deployed / drilled horizontal wells to be calculated, H 部署 / 完钻 is the thickness of high-quality reservoir in the area where the horizontal well to be deployed / drilled is located, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated, A is the EUR coefficient, and B is the EUR correction factor.
[0028] Furthermore, if the block where the deployed or completed well is located belongs to type three, the values of A and B can be obtained by substituting the production data of the wells already in production in the block into the formula, which is as follows:
[0029]
[0030]
[0031] Where, L 投1 is the horizontal section length of the production well 1, Φ 投1 is the target drilling rate of the production well 1, S 投1 is the well spacing of production well 1, H 投1 is the thickness of high-quality reservoir in the area where the production well 1 is located, EUR 投1 is the EUR of the production well 1, L 投2 is the horizontal section length of the production well 2, Φ 投2 is the target drilling rate of the production well 2, S 投2 is the well spacing of production well 2, H 投2 is the thickness of high-quality reservoir in the area where the production well 2 is located, EUR 投2 EUR for Well 2 in production.
[0032] Furthermore, if the block where the deployed well or completed well is located belongs to type 4, the value of A is 0.73 and the value of B is 9.76.
[0033] Due to the adoption of the above technical solution, the present invention has the following advantages: Through the present invention, different EUR prediction methods for deployment and completion of horizontal wells can be formed according to the production data conditions in different exploration and development stages, and the implementation effects of deployment wells and completion wells can be effectively and quickly predicted, and the implementation benefits can be evaluated, which is of great significance to accelerating the progress of block production capacity construction and ensuring the efficient development of shale gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments described in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.
[0035] Figure 1 Schematic diagram of a flow chart of a method for predicting EUR of shale gas deployment / completion horizontal wells at different exploration and development stages according to an embodiment of the present invention. DETAILED DESCRIPTION
[0036] The present invention will be further described with reference to the accompanying drawings and embodiments. The embodiments described are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by those skilled in the art should fall within the scope of protection of the embodiments of the present invention.
[0037] To ensure the profitable development of shale gas, it is necessary to predict the effectiveness of well deployment and completion before implementation, thereby evaluating the benefits of implementation. EUR is a key parameter for evaluating the effectiveness of gas well deployment. Rapidly and effectively predicting EUR is crucial for accelerating the construction of production capacity in these blocks and ensuring the profitable development of shale gas. Shale gas development blocks have different production data at different exploration and development stages, and different methods can be used to predict the EUR of shale gas horizontal wells based on these data. Therefore, this invention develops a method for predicting the EUR of shale gas deployment / completion horizontal wells at different exploration and development stages, based on the production data of shale gas blocks at different exploration and development stages, targeting both well deployment and completion.
[0038] See also Figure 1 The present invention provides an embodiment of a method for predicting EUR of shale gas deployment / completion horizontal wells at different exploration and development stages, which includes:
[0039] Step 1: Collect production data for the block where the horizontal well is deployed / drilled, including horizontal section length, target penetration rate, EUR data, production logging data, high-quality reservoir thickness, etc.
[0040] Step 2: Classify the blocks based on the production data of the blocks where the horizontal wells are deployed / drilled;
[0041]
[0042] Step 3: Get the EUR calculation parameters for different block types based on the block type:
[0043] Type 1, including standard well horizontal section length (L 标 ), target drilling rate (Φ 标 ), EUR(EUR 标 );
[0044] Type 2, including the EUR contribution per meter of each layer (EUR xi , xi represents different small layers);
[0045] Type 3, including the distribution of high-quality reservoir thickness, the thickness of high-quality reservoirs in production wells (2 or more) (H 投 ), horizontal section length (L 投 ), target drilling rate (Φ 投 ), well spacing (S 投 , the width of the fracturing range for the separately distributed production wells and the horizontal interval for the platform wells), EUR 投 .
[0046] Type 4 includes the distribution of high-quality reservoir thickness.
[0047] Step 4: Develop EUR forecast based on deployed / completed horizontal well data:
[0048] 1. If the block where the deployed or completed well is located belongs to Type 1, the EUR forecast is carried out as follows:
[0049] EUR 部署 / 完钻 =EUR 标 ×[(L 部署 / 完钻 ×Φ 部署 / 完钻 )÷(L 标 ×Φ 标 )]
[0050] Where, L 标 is the horizontal section length of the standard well, in meters; Φ 标 is the target drilling rate of standard wells, in %; EUR 标 EUR is the standard well, unit is 100 million cubic meters; L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, in meters; Φ 部署 / 完钻 is the target drilling rate of the deployed / completed horizontal well to be calculated, in %; EUR 部署 / 完钻 EUR is the number of deployed / completed horizontal wells to be calculated, in billion cubic meters.
[0051] 2. If the block where the deployed or completed well is located belongs to Type II, the EUR forecast is carried out as follows:
[0052]
[0053] Where, L xi-部署 / 完钻 The length of each layer encountered in the horizontal section of the deployed / completed horizontal well to be calculated, in meters; EUR xi The EUR contribution per meter of each small layer in the block, in billion cubic meters; EUR 部署 / 完钻 EUR is the number of deployed / completed horizontal wells to be calculated, in billion cubic meters.
[0054] 3. If the block where the deployed or completed well is located belongs to Type 3 or Type 4, the EUR forecast is carried out as follows:
[0055] EUR 部署 / 完钻 =A×ln(L 部署 / 完钻 ×Φ 部署 / 完钻 ×Φ 部署 / 完钻 ×H 部署 / 完钻 )-B
[0056] Where, L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, in meters; Φ 部署 / 完钻 is the target drilling rate of the deployed / drilled horizontal well to be calculated, in %; Φ 部署 / 完钻 H is the spacing between deployed / drilled horizontal wells to be calculated. The value for a single well is 400 m, and the value for a platform well is the spacing between adjacent horizontal sections of wells, in meters. 部署 / 完钻 The thickness of high-quality reservoir in the area where the horizontal well is deployed / drilled, in meters; EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated, in billion cubic meters; A is the EUR coefficient, in billion cubic meters / cubic meter; B is the EUR correction factor, in billion cubic meters / cubic meter.
[0057] 3.1. If the block where the deployed or completed well is located belongs to Type III, the values of A and B can be calculated by substituting the production data of the wells (two or more) that have been put into production in the block into the formula. The calculation formula is as follows:
[0058]
[0059]
[0060] Where, L 投1 is the horizontal section length of the production well 1, in meters; Φ 投1 is the target drilling rate of the production well 1, in %; S 投1 H is the well spacing of the production well 1, which is 400m for a single well and 400m for a platform well, and is the horizontal spacing between adjacent wells, in meters;投1 The thickness of high-quality reservoir in the area where the production well 1 is located, in meters; EUR 投1 is the EUR of the production well 1, in billion cubic meters; L 投2 is the horizontal section length of the production well 2, in meters; Φ 投2 is the target drilling rate of the production well 2, in %; S 投2 H is the well spacing of the production well 2, which is 400m for a single well and 400m for a platform well, and the horizontal spacing between adjacent wells, in meters; 投2 The thickness of high-quality reservoir in the area where the production well 2 is located, in meters; EUR 投2 EUR for the production well 2, in billion cubic meters;
[0061] 3.2. If the block where the deployed or completed well is located belongs to Type 4, the value of A is 0.73, in units of 100 million cubic meters; the value of B is 9.76, in units of 100 million cubic meters.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.
Claims
1. A method for predicting EUR of shale gas deployment / completion horizontal wells at different exploration and development stages, characterized by: include: Production data for the blocks where deployed / completed horizontal wells are located is collected and, based on this data, the block types are classified. EUR calculation parameters corresponding to the different block types are obtained. Based on the obtained EUR calculation parameters corresponding to the different block types, the EUR of the deployed / completed horizontal wells is predicted.
2. The method according to claim 1, characterized in that The production data include the length of the horizontal section of the implemented wells, the target drilling rate, EUR data, production logging data, and the thickness of high-quality reservoirs.
3. The method according to claim 1, characterized in that The different block types include Type 1, Type 2, Type 3 and Type 4; Type 1 indicates that there are many producing wells, abundant production data, and a standard well model can be formed; Type 2 indicates that there are few producing wells and less production data, but there is production logging data, and the EUR contribution of each sub-layer can be analyzed; Type 3 indicates that there is no production logging data, but there are producing wells, and high-quality reservoir data and production data can be obtained; Type 4 indicates that there are no producing wells, but there is evaluation well data, and high-quality reservoir data can be obtained.
4. The method according to claim 1, wherein The EUR calculation parameters corresponding to different block types are obtained according to different block types, including: According to type 1, the EUR calculation parameters obtained include the horizontal section length L of the standard well 标 , target drilling rate Φ 标 , the ultimate recoverable reserves of standard wells EUR 标 ; According to type 2, the EUR calculation parameters obtained include the EUR contribution per meter of each small layer in the block; According to Type 3, the EUR calculation parameters obtained include the distribution of high-quality reservoir thickness and the high-quality reservoir thickness H of the producing wells. 投 , horizontal section length L 投 , target drilling rate Φ 投 , well spacing S 投 , EUR 投 ; According to Type 4, the EUR calculation parameters obtained include the thickness distribution of high-quality reservoirs.
5. The method according to claim 1, wherein The EUR calculation parameters corresponding to different block types are obtained, and the EUR of the deployed / completed horizontal well is predicted, including: If the block where the deployed or completed well is located belongs to Type 1, the EUR forecast is carried out as follows: EUR 部署 / 完钻 =EUR 标 ×[(L 部署 / 完钻 ×Φ 部署 / 完钻 )÷(L 标 ×Φ 标 )] Where, L 标 is the horizontal section length of the standard well, Φ 标 is the target drilling rate of standard wells, EUR 标 For standard well EUR, L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, Φ 部署 / 完钻 is the target drilling rate of the deployed / completed horizontal well to be calculated, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated.
6. The method according to claim 1, characterized in that The EUR calculation parameters corresponding to different block types are obtained, and the EUR of the deployed / completed horizontal well is predicted, including: If the block where the deployed or completed well is located belongs to Type 2, the EUR forecast is carried out as follows: Where, L xi-部署 / 完钻 EUR is the length of each layer encountered in the horizontal section of the deployed / completed horizontal well to be calculated. xi EUR is the EUR contribution per meter of each layer in the block, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated.
7. The method according to claim 1, characterized in that The EUR calculation parameters corresponding to different block types are obtained, and the EUR of the deployed / completed horizontal well is predicted, including: If the block where the deployed or completed well is located belongs to Type 3 or Type 4, the EUR forecast is carried out as follows: EUR 部署 / 完钻 =A×ln(L 部署 / 完钻 ×Φ 部署 / 完钻 ×S 部署 / 完钻 ×H 部署 / 完钻 )-B Where, L 部署 / 完钻 is the length of the horizontal section of the deployed / drilled horizontal well to be calculated, Φ 部署 / 完钻 is the target drilling rate of the deployed / drilled horizontal well to be calculated, S 部署 / 完钻 is the spacing between deployed / drilled horizontal wells to be calculated, H 部署 / 完钻 is the thickness of high-quality reservoir in the area where the horizontal well to be deployed / drilled is located, EUR 部署 / 完钻 is the EUR of the deployed / completed horizontal well to be calculated, A is the EUR coefficient, and B is the EUR correction factor.
8. The method according to claim 7, characterized in that If the block where the deployed or completed well is located belongs to type 3, the values of A and B can be obtained by substituting the production data of the wells already in production in the block into the formula. The calculation formula is as follows: Where, L 投1 is the horizontal section length of the production well 1, Φ 投1 is the target drilling rate of the production well 1, S 投1 is the well spacing of production well 1, H 投1 is the thickness of high-quality reservoir in the area where the production well 1 is located, EUR 投1 is the EUR of the production well 1, L 投2 is the horizontal section length of the production well 2, Φ 投2 is the target drilling rate of the production well 2, S 投2 is the well spacing of production well 2, H 投2 is the thickness of high-quality reservoir in the area where the production well 2 is located, EUR 投2 EUR for Well 2 in production.
9. The method according to claim 7, characterized in that If the block where the deployed or completed well is located belongs to type 4, the value of A is 0.73 and the value of B is 9.76.