CN-121993145-A - Quantitative evaluation method for oil-water well blocking degree

Abstract

The invention discloses a quantitative evaluation method for the clogging degree of an oil-water well, which comprises the specific processes of step 1, collecting data of the clogged well, step 2, evaluating the clogging degree of a certain day according to the data collected in step 1, step 3, evaluating the clogging degree in a stage time according to the clogging degree of a certain day obtained in step 2, and step 4, evaluating the clogging degree in the whole production stage according to the clogging degree in the stage time obtained in step 3. The method solves the problems of high cost and poor accuracy of the existing evaluation of the plugging degree of the oil-water well.

Inventors

• HUANG TING
• HE HENG
• LI ZHUANHONG
• DONG QI
• YU JINZHU
• REN JIAWEI
• ZHOU TAO
• WANG DEYU
• YAN CHANGHAO
• BAI XIAOHU
• LI XIANGPING
• DU XIANFEI
• FENG FEI
• BU JUN
• WANG FEI

Assignees

• 中国石油天然气股份有限公司

Dates

Publication Date

20260508

Application Date

20241101

Claims (10)

1. 1. The quantitative evaluation method for the clogging degree of the oil-water well is characterized by comprising the following steps of: Step 1, collecting data of a blocked well; step 2, evaluating the clogging degree of a certain day according to the data collected in the step 1; step 3, evaluating the blocking degree in the stage time according to the blocking degree of a certain day obtained in the step 2; And step 4, evaluating the blocking degree of the whole production stage according to the blocking degree in the stage time obtained in the step 3.
2. 2. The quantitative evaluation method for the plugging degree of the oil-water well according to claim 1, wherein in the step 1, when the plugged well is an oil well, the collected data comprise daily liquid production amount change, liquid density, static liquid level and dynamic liquid level from production to the current time period; when the plugged well is a water well, the collected data comprise daily injection allocation after production and actual daily injection.
3. 3. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 2, wherein when the clogged well is an oil well, the specific process of step 2 is as follows: Step 2.1, converting the production pressure difference according to the data of the static liquid level and the dynamic liquid level, wherein the production pressure difference is = (static liquid level-dynamic liquid level) and the liquid density is g; Wherein g is gravity acceleration, m/s 2 ; 2.2, under the production pressure difference obtained in the step 2.1, adopting numerical simulation software to construct a control model, obtaining a simulation result, drawing a daily production liquid change curve of the plugged well along with the production time according to the simulation result, and obtaining a fitting daily production liquid amount according to the daily production liquid change curve of the plugged well along with the production time; step 2.3, defining an interference coefficient F; when a reverse interference factor exists, the value range of F is 1-1.5; When a forward interference factor exists, the value range of F is 0.5-1; f takes a value of 1 when the oil well is normally produced; Step 2.4, calculating the blockage degree of a certain day according to the actual daily liquid yield data of the blocked well and the fitting daily liquid yield obtained in the step 2.2; (1) in the formula (1), the components are as follows, For the degree of blockage of an oil well on a certain day, qe is the daily liquid yield fitted on a certain day, and q1 is the actual daily liquid yield on a certain day.
4. 4. The method for quantitatively evaluating the plugging degree of an oil-water well according to claim 3, wherein in the step 2.3, the reverse interference factors comprise pump leakage, broken sucker rod, scale formation and wax precipitation of a shaft, repeated fracturing of an adjacent well, acidification and plugging removal of the adjacent well, water well conversion and production, small stroke adjustment, small pump depth adjustment and small pump diameter adjustment; The forward interference factors include flushing, fracturing of the blocked well, acidizing unblocking of the blocked well, adjusting the stroke frequency, adjusting the pump depth and adjusting the pump diameter.
5. 5. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 3, wherein in step 3, the evaluation expression of the clogging degree in the stage time is: (2) in the formula (2), the amino acid sequence of the compound, Is the degree of blockage during the oil well stage time, For the amount of daily liquid production of the fit on day i, And t is the actual daily liquid yield on the i day and the production time.
6. 6. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 3, wherein in step 4, the evaluation expression of the clogging degree in the whole production stage is: (3) in the formula, And b is a fitting constant of a daily fluid production curve of the plugged well along with the production time in the step 2.2, c is a fitting constant of a collected daily fluid production curve of the plugged well along with the production time, m is a production curve index fitted from production to k days, and m' is a practical production curve index from production to k days.
7. 7. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 2, wherein when the clogged well is a water well, the specific process of step 2 is as follows: Step 2.1, defining a well interference coefficient F ' ; When a reverse interference factor exists, the value range of F ' is 1-1.5; when a forward interference factor exists, the value range of F ' is 0.5-1; when the water well is normally filled with water, F ' takes a value of 1; step 2.2, evaluating the clogging degree of a certain day, wherein the expression is as follows: (4) In the formula (4), the amino acid sequence of the compound, For the blockage degree of a well on a certain day, p is the injection allocation amount on the day after production, and p 1 is the actual injection amount on the day.
8. 8. The quantitative evaluation method for the plugging degree of the oil-water well according to claim 7, wherein in the step 2.1, the reverse interference factors comprise poor stratum physical properties and scale formation of a well bore, and the forward interference factors comprise well flushing and plugging removal recovery measures.
9. 9. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 7, wherein in step 3, the evaluation expression of the clogging degree in the stage time is: (5) In the formula (5), the amino acid sequence of the compound, For the degree of blockage during the water well phase, The amount of the injection is allocated for the day of the i day, The actual injection amount on day i, d is time.
10. 10. The quantitative evaluation method for the clogging degree of an oil-water well according to claim 7, wherein in step 4, the evaluation expression of the clogging degree in the whole production stage is: (6) In the formula (6), the amino acid sequence of the compound, The blocking degree of the water well in the whole production stage is shown, and T is the time for opening and injecting the water well.

Description

Quantitative evaluation method for oil-water well blocking degree Technical Field The invention belongs to the technical field of reservoir reconstruction, and particularly relates to a quantitative evaluation method for the clogging degree of an oil-water well. Background Through years of development of oil fields, different degrees of damage to reservoirs occur, partial oil well liquid supply is insufficient, water well injection pressure rises, blocking phenomenon is serious, normal production is influenced, therefore, development of evaluation of blocking degree of oil-water wells is indispensable, and blocking removal can be carried out by taking targeted measures according to blocking degree. The existing blocking degree evaluation method is roughly divided into an indoor experiment method and an on-site test method, wherein the indoor experiment is used for quantitatively evaluating blocking degrees of CO 2 pore throat interaction on pore throats with different radiuses by calculating the spectrum distribution and the frequency area difference of core saturated fluid T2 before and after the experiment, but the method has higher requirements on experimental equipment and high cost, and the other method is used for on-site monitoring the oil pressure of a reference well, taking the oil pressure of the well to be evaluated and the oil pressure of the reference well as difference values, and evaluating the blocking degree of the well to be evaluated. Disclosure of Invention The invention aims to provide a quantitative evaluation method for the clogging degree of an oil-water well, which solves the problems of high cost and poor accuracy of the conventional evaluation of the clogging degree of the oil-water well. The technical scheme adopted by the invention is that the quantitative evaluation method for the clogging degree of the oil-water well is implemented according to the following steps: Step 1, collecting data of a blocked well; step 2, evaluating the clogging degree of a certain day according to the data collected in the step 1; step 3, evaluating the blocking degree in the stage time according to the blocking degree of a certain day obtained in the step 2; And step 4, evaluating the blocking degree of the whole production stage according to the blocking degree in the stage time obtained in the step 3. The present invention is also characterized in that, In the step 1, when the plugged well is an oil well, the collected data comprise daily liquid production amount change, liquid density, static liquid level and dynamic liquid level from production to the current time period; when the plugged well is a water well, the collected data comprise daily injection allocation after production and actual daily injection. When the plugged well is an oil well, the specific process of the step 2 is as follows: Step 2.1, converting the production pressure difference according to the data of the static liquid level and the dynamic liquid level, wherein the production pressure difference is = (static liquid level-dynamic liquid level) and the liquid density is g; Wherein g is gravity acceleration, m/s 2; 2.2, under the production pressure difference obtained in the step 2.1, adopting numerical simulation software to construct a control model, obtaining a simulation result, drawing a daily production liquid change curve of the plugged well along with the production time according to the simulation result, and obtaining a fitting daily production liquid amount according to the daily production liquid change curve of the plugged well along with the production time; step 2.3, defining an interference coefficient F; when a reverse interference factor exists, the value range of F is 1-1.5; When a forward interference factor exists, the value range of F is 0.5-1; f takes a value of 1 when the oil well is normally produced; Step 2.4, calculating the blockage degree of a certain day according to the actual daily liquid yield data of the blocked well and the fitting daily liquid yield obtained in the step 2.2; (1) in the formula (1), the components are as follows, For the degree of blockage of an oil well on a certain day, qe is the daily liquid yield fitted on a certain day, and q1 is the actual daily liquid yield on a certain day. In the step 2.3, the reverse interference factors comprise pump leakage, breaking and releasing of a sucker rod, scaling and waxing of a shaft, repeated fracturing of an adjacent well, acidification and blocking removal of the adjacent well, water well conversion and extraction, small stroke adjustment, small pump depth adjustment and small pump diameter adjustment; The forward interference factors include flushing, fracturing of the blocked well, acidizing unblocking of the blocked well, adjusting the stroke frequency, adjusting the pump depth and adjusting the pump diameter. In step 3, the evaluation expression of the clogging degree in the stage time is: (2) in the formula (2), the amino aci