Multi-hydrogen acid construction process suitable for modification of sandstone reservoir

A technology for reservoir reconstruction and construction technology, which is applied in the directions of drilling composition, production fluid, wellbore/well components, etc., and can solve the problems of fast reaction speed, difficulty in effectively solving drilling and completion, short penetration distance, etc.

Inactive Publication Date: 2018-05-18
CNPC BOHAI DRILLING ENG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the conventional acidizing fluid system including conventional soil acid is applied in the sandstone acidizing process, it shows fast reaction speed, short penetrat

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Example 1: Acidification of injection wells in Hua XX-1 well

[0031] The acidizing layer in this well section is the 126-132# layer of Liu 1st Member, with a total thickness of 14.4m. The initial daily water injection volume is 6 ~ 15m 3 , The water injection pressure is 24MPa. According to a comprehensive analysis, with the prolongation of water injection time, the impurities contained in the layer continue to accumulate near the oil layer in the wellbore, blocking the formation pore and throat channels, resulting in a decrease in the water absorption capacity of the formation and an increase in the water injection pressure. In order to ensure the normal water injection of the well, it was decided to carry out acidizing injection.

[0032] The polyhydrogen acid system is used to carry out the polyhydric acid construction process for the well, and the acidizing construction steps are as follows:

[0033] S1, preparation 10m 3 The well pretreatment fluid, with 0.5m 3...

Embodiment 2

[0039] Example 2: Acidification of injection wells in Hua XX-2 well

[0040] The acidizing layer in this well section is the 197-212# layer of Liu 1st Member, with a total thickness of 10.6m. At the initial stage of betting, the daily water injection volume is 20m 3 , the injection pressure is 17MPa, which basically reaches the dispensing volume. With the prolongation of water injection time, the injection pressure gradually rises to 24MPa, and the daily water injection volume is only 16m 3 , unable to meet the required dispensing volume. According to a comprehensive analysis, the main reason for the difficulty of water injection in this well is that the physical properties of this layer are poor, and some pollution is caused during the operation and water injection process, which leads to an increase in injection pressure.

[0041] The well adopts the polyhydric acid construction process to deal with the blockage caused by the mud pollution near the well. The construction ...

Embodiment 3

[0048] Example 3: Acidification of injection wells in Hua XX-3 well

[0049] The acidizing layer in this well section is the 300-313# layer in the IV oil group of Liu 1 member, with a total thickness of 33.0m. The initial daily water injection volume is less than 5m 3 , The water injection pressure is 27.5MPa. The lithology of the target formation is pebble-bearing fine sandstone, loose, and the cuttings are loose sand. According to a comprehensive analysis, the main reason for the difficulty of water injection in this well is that the physical properties of the oil layer are poor, and impurities around the wellbore pollute the low-permeability layer, resulting in low water absorption capacity and high injection pressure.

[0050] The well adopts the polyhydric acid construction process to deal with the blockage caused by the mud pollution near the well. The construction steps are as follows:

[0051] S1, preparation 10m 3 The well pretreatment fluid, with 0.5m 3 / min dis...

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Abstract

The invention discloses a multi-hydrogen acid construction process suitable for modification of a sandstone reservoir. The multi-hydrogen acid construction process suitable for modification of the sandstone reservoir successively comprises the following steps: step one, carrying out replacing on 10-20 m<3> of a pre-treating solution or a mutual solvent under the conditions that the discharge capacity is 0.1-0.5 m<3>/min, and the pump pressure is 1-34 MPa; step two, carrying out extrusion on 10-20 m<3> of pad-acid under the conditions that the discharge capacity is 0.1-0.5 m<3>/min, and the pump pressure is 1-34 MPa; step three, carrying out extrusion on 20-50 m<3> of main body acid under the conditions that the discharge capacity is 0.1-0.5 m<3>/min, and the pump pressure is 1-34 MPa; andstep four, carrying out extrusion on 5-20 m<3> of water well displacing liquid or oil well displacing liquid under the conditions that the discharge capacity is 0.2-1 m<3>/min and the pump pressure is1-34 MPa to finish acidification modification on the sandstone reservoir under a water well or an oil well. The multi-hydrogen acid construction process suitable for modification of the sandstone reservoir is used for carrying out augmented injection on an acidized horizon, blockage of a pore throat channel of a stratum is relieved, the water injection amount is increased, water injection pressure is reduced, the oil and gas recovery efficiency is improved, and compared with a conventional acidifying process, the multi-hydrogen acid construction process suitable for modification of the sandstone reservoir is more environmentally friendly and safer, and provides a safe operation condition for human beings, equipment and environments.

Description

technical field [0001] The invention relates to the technical field of oil and gas field reservoir transformation, in particular to a polyhydric acid construction technology suitable for sandstone reservoir transformation. Background technique [0002] The acidizing of oil and water wells in sandstone reservoirs is mainly by injecting acid liquids containing hydrochloric acid, hydrofluoric acid, and fluoboric acid into the formation, so that the acid liquids react with many siliceous minerals, such as quartz and clay, and remove blockages near the wellbore (such as Iron oxide, ferrous sulfide, clay, etc.) to restore formation permeability; it can also dissolve part of the rock near the wellbore, expand the throat of the pore structure, and increase the formation permeability. However, when the conventional acidizing fluid system including conventional soil acid is applied in the sandstone acidizing process, it shows fast reaction speed, short penetration distance, easy forma...

Claims

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Application Information

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IPC IPC(8): E21B43/22C09K8/78
CPCE21B43/16C09K8/78
Inventor 刘音张世林杨东海吴兆亮黄其张伟辉刘位李楠王晓磊李欣姜有才高秀君
Owner CNPC BOHAI DRILLING ENG
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