Method for guiding single well benefit improvement of oil well

Abstract

The invention discloses a method for guiding single well benefit improvement of an oil well, which is implemented according to the following steps: step 1, calculating limit single well benefit yield, determining whether the well can continue well opening operation or not, and if the well can continue well opening operation, entering an optimization process of step 2; step 2, optimizing the intermittent opening period of the single well: 2.1) determining the well shut-in time of the periodic oil production; 2.2) determining the well opening time of the periodic oil production; therefore, the optimized interval period can be determined. The invention belongs to the technical field of oil production and gas production in the petroleum industry, and solves the problems that for a low-yield and low-efficiency oil well in the prior art, the single-well production benefit condition of the oil well is not comprehensively judged in combination with the liquid level recovery condition and the production condition, and benefit improvement cannot be achieved in a targeted mode.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas production technology in the petroleum industry, and relates to a method for guiding the improvement of single-well efficiency in oil wells. Background Technology

[0002] Evaluation of the efficiency of individual oil wells is beneficial for achieving efficient development. Based on the input and output of a single well, its economic benefits are assessed, and policy adjustments are made based on the evaluation results to avoid inefficient and ineffective production and improve the development efficiency of individual wells. Therefore, formulating a single-well efficiency improvement plan is of great significance for reducing operating costs, minimizing production impact, and improving the overall development efficiency of the oilfield. In actual production, various factors influence the efficient development of individual wells, mainly including the influence of production methods, production systems, development methods, and operating models. Conventional methods for reducing inefficiency and ineffectiveness in individual wells often involve intermittent extraction of oil wells within a specific area of ​​a block or a single oil well. The drawback of this method is that it lacks a systematic evaluation standard and improvement measures for the efficient development of contiguous low-yield and inefficient wells from an economic perspective. It cannot be applied on a large scale through a scientific and effective evaluation system, and the improvement effect of single-well intermittent extraction on oilfield efficiency development is limited.

[0003] Currently, there is a lack of systematic and in-depth research on single-well efficiency development systems. There is a lack of understanding and summarization of existing oil well inter-well opening patterns and their improvement methods. Local implementation methods are simplistic and lack scalability, resulting in limited efficiency improvement effects. Therefore, further in-depth research is needed to develop a new method to guide single-well efficiency development in oil wells. Summary of the Invention

[0004] The purpose of this invention is to provide a method for guiding the improvement of single-well efficiency in oil wells, and to solve the problem that existing technologies for low-yield and low-efficiency oil wells do not take into account the recovery of the fluid level and the production situation to comprehensively judge the single-well production efficiency of the oil well, and thus cannot achieve targeted efficiency improvement.

[0005] The technical solution adopted in this invention is a method for guiding the improvement of single-well efficiency in oil wells, implemented according to the following steps:

[0006] Step 1: Calculate the maximum single-well efficiency production to determine whether the well can continue to be operated. If it is determined that the well can continue to be operated, proceed to the optimization process in Step 2.

[0007] Step 2: Optimize the intermittent opening cycle of a single well.

[0008] 2.1) Determine the shut-in time for cyclic oil production:

[0009] 2.2) Determine the well opening time for cyclic oil production;

[0010] Therefore, the optimal intermittent opening period can be determined.

[0011] The beneficial effects of this invention are that, for low-yield and inefficient oil wells, targeted efficiency improvement measures can be formulated based on their fluid level recovery and production status, thereby maximizing the production efficiency of a single well; compared with the conventional single intermittent method, it increases the evaluation criteria and more accurately reduces cost input; the identification criteria are simple and highly operable, which has a certain promoting effect on the application of this technology. Attached Figure Description

[0012] Figure 1 This is a graph showing the relationship between the yield and time of the intermittent well operation method of this invention;

[0013] Figure 2 This is a curve showing the relationship between the daily fluid production of a single well and the well shutdown time when the wellbore stores 5 cubic meters of fluid using the method of this invention;

[0014] Figure 3 This is a schematic diagram of the well fluid level recovery in Embodiment 1 of the method of the present invention;

[0015] Figure 4 This is a diagram showing the change in the indicator diagram after the test well is opened in Embodiment 1 of the present invention. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0017] The method of this invention aims to maximize the benefits of a single well by evaluating and optimizing production methods. Through a comprehensive evaluation of the economic benefits of both cyclic oil production and dredging oil production, the optimal production method and the best production system are determined.

[0018] The method of the present invention for guiding the improvement of single-well efficiency in oil wells is implemented according to the following steps:

[0019] Construct a template for the maximum single-well efficiency and production rate in cyclic oil recovery.

[0020] Reference Figure 1 By employing discontinuous production methods, the goal is to extract the maximum amount of liquid in the shortest time, thereby improving the economic efficiency of oil wells. The core objective is to evaluate the relationship between electricity costs and the profitability of a single well. Other costs are analyzed based on fixed values ​​determined from the actual expenses incurred in the current year.

[0021] Step 1: Calculate the maximum single-well production efficiency to determine whether the well can continue operating.

[0022] The principle expression is: "Single well output benefit" minus "single well fixed production cost" minus "actual electricity consumption cost", the result value is not less than zero;

[0023] The function expression is: N×Q 油 -C 固 -A×T≥0,(1)

[0024] Where N is the price of crude oil, in yuan / ton; Q 油 Indicates daily oil production per well, in tons; C 固 A represents the fixed production cost per well, in yuan / day (this is the production cost excluding electricity, and is generally set to a fixed value); A represents the production electricity cost, in yuan / hour (generally set to a constant of 2.5 yuan / hour); T represents the production time, in hours.

[0025] Transform equation (1) into: Q 油 ≥(C 固 +A×T)÷N, (2)

[0026] The minimum limit of single-well efficiency production is obtained: Q 油 =(C 固 +A×T)÷N, (3)

[0027] Let Q 效益 This represents the average single-well efficiency of the current oil wells in the oil field.

[0028] If the maximum single-well efficiency production of this well If the flow rate is [tons / hour], then well opening will commence;

[0029] If the maximum single-well efficiency production of this well If the capacity is less than 1 ton / hour, a long-term shutdown will be implemented.

[0030] Step 1 determines whether the well can continue operating, and then proceeds to the optimization process in Step 2.

[0031] Step 2: Optimize the intermittent opening cycle of a single well.

[0032] 2.1) Determine the well shut-in time:

[0033] Based on the fluid level recovery method, the shut-in time is determined according to the single well's fluid supply capacity to ensure maximum crude oil production. Specifically:

[0034] Based on the single-well fluid supply capacity, pressure recovery curves of single wells with different submersion depths were analyzed. Compared with the production fluid volume estimation method, the recovery time for the wellbore storage volume to reach 5 cubic meters or more under different fluid volumes is much longer than theoretically calculated. This is especially true for low-volume wells with a single-well fluid volume of 1 cubic meter; the shut-in time required to recover the wellbore storage volume to 5 cubic meters is over 10 days. For wells with a production volume of over 1 cubic meter, the shut-in time decreases as the fluid volume increases. Figure 2 ,

[0035] 2.2) Determine the well opening time.

[0036] Based on the annular volumetric fluid volume and time of the oil casing above the pump set of the production pump, the well opening time is determined by applying the single-well theoretical displacement and pump efficiency calculations. The function is:

[0037]

[0038] Among them, T 开井 Indicates well opening time, in hours; Q 液 This indicates the volume of liquid in the annulus above the pump casing, in cubic meters; N0 indicates pump efficiency, in %; D p The pump diameter is indicated in millimeters; n represents the stroke in meters; and r represents the number of strokes per minute.

[0039] In summary, based on actual production conditions, the well shutdown time and well opening time of a single well are strongly correlated with its fluid supply capacity. Combined with the fluid level recovery situation, a reasonable intermittent opening cycle can be determined.

[0040] Example 1

[0041] According to the above steps of the periodic oil recovery method of the present invention, Example 1 selects one conventional intermittent well for testing. The test object is "Well No. 1" of a certain oilfield.

[0042] The pump has a diameter of 28 mm, a stroke rate of 5.0 strokes / minute, a stroke of 2.5 meters, a pump efficiency of 42%, and a daily liquid production of 1.1 cubic meters. In March 2020, the pump was operated on a 1-day-on, 1-day-off schedule.

[0043] According to formula Q 油 =(C 固 Calculate the maximum single-well yield of "Well No. 1" using the formula: +A×T)÷N.

[0044] Among them, C 固 Given: A: 1785 yuan / day, B: 2.5 yuan / hour, C: 24 hours, D: 4088 yuan, we can derive Q. 油 =0.45 tons / day. The maximum single-well production of this well is 0.45 tons / day. Currently, the single-well production is 0.82 tons / day, and the efficiency is positive, confirming that the oil well is profitable in continuous production.

[0045] To further improve the efficiency of a single well, a suitable and reasonable production cycle is determined after optimization according to the method of this invention.

[0046] Determine the well shut-in time: See Figure 3 By using the liquid level recovery method and combining the relationship between the daily production of a single well and the well shutdown time for well storage, the optimal shut-in time was determined to be 5 days.

[0047] Determine well opening time: See Figure 4 The annular fluid volume was determined to be 2.5 cubic meters using the dynamometer card method, combined with formula (4):

[0048] The optimal well opening time was determined to be 12 hours.

[0049] It was finally determined that the well's intermittent operation cycle would be optimized from the original 1 day on and 1 day off to 5 days off and 12 hours on, resulting in a monthly cost saving of 1,440 yuan per well.

[0050] As can be seen, following the steps of the method of the present invention, the production efficiency of the oil well in Example 1 is within the range of optimal intermittent benefits, which fully meets the production requirements.

[0051] Example 2

[0052] Referring to Example 1, the No. 2 well in an oil field was tested according to the above steps of the method of the present invention.

[0053] The well has a daily fluid production of 0.6 cubic meters and a daily oil production of 0.42 tons. It is a normally open well with a pump diameter of 28 mm, a stroke rate of 2.5 times / minute, a stroke of 2.5 meters, and a pump efficiency of 30%.

[0054] According to formula Q 油 =(C 固 Calculate the maximum single-well production efficiency of Well No. 2 in this oilfield using (+A×T)÷N.

[0055] Among them, C 固 Given: A: 1785 yuan / day, B: 2.5 yuan / hour, C: 24 hours, D: 4088 yuan, we can derive Q. 油 =0.45 tons / day. The maximum single-well production of this well is 0.45 tons / day, which means that the current single-well production is 0.42 tons / day, resulting in negative efficiency. The only solution is to optimize the system and reduce costs.

[0056] The reasonable interval between openings is determined according to the method of this invention, and the system optimization scheme is as follows:

[0057] Determining the shut-in time: By using the fluid level recovery method and combining the relationship between the daily fluid production of a single well and the well storage shutdown time, the optimal shut-in time was determined to be 7 days.

[0058] Determining the well opening time: The annular fluid volume was determined to be 2.0 cubic meters using the dynamometer card method, combined with formula (4):

[0059] The optimal well opening time was determined to be 1 day.

[0060] Ultimately, it was determined that the optimal intermittent operation cycle for this well was 7 days of shutdown and 1 day of operation, resulting in a monthly cost saving of 1008 yuan per well after optimization.

[0061] As can be seen, following the steps of the method of the present invention, the production efficiency of the oil well in Example 2 is within the range of optimal intermittent benefits, which fully meets the production requirements.

[0062] Example 3

[0063] Referring to Example 1, the No. 3 well in an oil field was tested according to the above steps of the method of the present invention.

[0064] The well has a daily production capacity of 1.2 cubic meters, is a normally operating well, has a pump diameter of 28 mm, a stroke rate of 3.5 times / minute, a stroke of 2.5 meters, and a pump efficiency of 11.6%.

[0065] According to formula Q 油 =(C 固 Calculate the maximum single-well yield of well No. 3 by multiplying A by T by N.

[0066] Among them, C 固 Given: A: 1785 yuan / day, B: 2.5 yuan / hour, C: 24 hours, D: 4088 yuan, we can derive Q. 油 =0.45 tons / day. The maximum effective production of this well is 0.45 tons / day. Currently, the single well production is 0.39 tons / day, resulting in negative benefits. Only through system optimization and cost reduction can the problem be solved.

[0067] The optimized system for the inter-opening cycle according to the method of this invention is as follows:

[0068] Determining the shut-in time: By using the fluid level recovery method and combining the relationship between the daily fluid production of a single well and the well storage shutdown time, the optimal shut-in time was determined to be 16 hours.

[0069] Determining the well opening time: The annular fluid volume was determined to be 3.0 cubic meters using the dynamometer card method, combined with formula (4):

[0070] The optimal well opening time was determined to be 8 hours.

[0071] Ultimately, it was determined that the optimal well-opening cycle should be optimized to 8 hours of operation and 16 hours of shutdown, resulting in a monthly cost saving of 960 yuan per well.

[0072] As can be seen, following the steps of the method of the present invention, the production efficiency of the oil well in Example 3 is within the range of optimal intermittent benefits, which fully meets the production requirements.

[0073] Example 4

[0074] Referring to Example 1, the No. 4 well in an oil field was tested according to the above steps of the method of the present invention.

[0075] The well has a daily production capacity of 0.5 cubic meters, is a normally open well, has a pump diameter of 28 mm, a stroke rate of 2.5 times / minute, a stroke of 2.5 meters, and a pump efficiency of 7.9%.

[0076] According to formula Q 油 =(C 固 Calculate the maximum single-well yield of well No. 4 by multiplying A by T by N.

[0077] Among them, C 固 Given: A: 1785 yuan / day, B: 2.5 yuan / hour, C: 24 hours, D: 4088 yuan, we can derive Q. 油 =0.45 tons / day. The maximum single-well production of this well is 0.45 tons / day. Currently, the single-well production is 0.19 tons / day, resulting in negative efficiency. Only through system optimization and cost reduction can the problem be solved.

[0078] The optimized system for the inter-opening cycle according to the method of this invention is as follows:

[0079] Determining the shut-in time: By using the fluid level recovery method and combining the relationship between the daily fluid production of a single well and the well storage shutdown time, the optimal shut-in time was determined to be 4 days.

[0080] Determining the well opening time: Using the dynamometer card method, the annular fluid volume was determined to be 1.8 cubic meters, combined with formula (4):

[0081] The optimal well opening time was determined to be 1 day.

[0082] Ultimately, it was determined that the optimal well-opening cycle should be optimized to 1 day open and 4 days closed, resulting in a monthly cost saving of 1,152 yuan per well.

[0083] As can be seen, following the steps of the method of the present invention, the production efficiency of the oil well in Example 4 is within the range of optimal intermittent benefits, which fully meets the production requirements.

Claims

1. A method for guiding the single well benefit improvement of an oil well, characterized in that, The following steps are implemented: Step 1, calculating the limit single well benefit production, determining whether the well can continue to open well operation, if it is determined that the well can continue to open well operation, then entering the optimization process of step 2; Step 2, optimizing the single well's interval opening cycle, 2.1) determining the shut-in time of the cycle oil production: 2.2) determining the opening time of the cycle oil production; Thus, the optimized interval opening cycle can be determined.

2. The method for guiding the single-well benefit improvement of an oil well according to claim 1, characterized in that: In step 1, the specific process of calculating the limit single well benefit production is: The function expression is: N x Q 油 -C 固 -A x T ≥ 0, (1) Wherein, N is the crude oil price, yuan / ton; Q 油 Indicates single well daily oil production, tons; C 固 Indicates single well fixed production cost, yuan / day; A is the production electricity fee, yuan / hour; T is the production time, hours; Transforming equation (1) to: Q 油 ≥(C 固 +A×T)÷N, (2) to get the ultimate single well benefit production: Q 油 =(C 固 +A×T)÷N. (3).

3. The method for guiding the single-well benefit improvement of an oil well according to claim 2, characterized in that: In step 1, the specific process of determining whether the well can continue to open well operation is: Let Q 效益 be the average single well performance of the current oil wells of the oil field, If the well limit single well benefit production tons / hour, then the well is opened; If the well limit single well benefit production tons / hour, then long-term shut-in is implemented.

4. The method for guiding the single-well benefit improvement of an oil well according to claim 1, characterized in that: In the step 2.1), when determining the shut-in time, According to the single well liquid supply capacity, the pressure buildup curve of the single well with different submergence is selected for analysis, and compared with the production liquid volume calculation method, the recovery time of the wellbore reservoir liquid volume reaching more than 5 cubic meters under different liquid volume is longer than the theoretical calculation.

5. The method for guiding the single-well benefit improvement of an oil well according to claim 4, characterized in that: Further, for the single well liquid volume of 1 cubic meter of low liquid volume well, the wellbore reservoir liquid volume recovery to 5 cubic meters requires more than 10 days of shut-in time; for the well with liquid volume of more than 1 cubic meter, the shut-in time decreases with the increase of liquid volume.

6. The method for guiding the single-well benefit improvement of an oil well according to claim 1, characterized in that: In step 2.2), according to the annular volume liquid volume time of the pump hanging above the produced pump, the single well theoretical displacement and pump efficiency are applied to determine the opening time, and the function is: Where, T 开井 represents the open well time, hours; Q 液 represents the liquid volume in the annulus above the pump, cubic meters; N0represents the pump efficiency, %; D p represents the pump diameter, millimeters; n represents the stroke, meters; and r represents the stroke frequency, times / minute.

7. The method for guiding the single-well benefit improvement of an oil well according to claim 1, characterized in that: When determining the shut-in time, the liquid level recovery method is implemented.

8. The method for guiding the single-well benefit improvement of an oil well according to claim 1, characterized in that: When determining the opening time, the dynamometer card method is implemented.

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