Stepwise dissolution and plugging removal method for oil and water wells

An oil-water well and corrosion technology, which is applied in the direction of earthwork drilling, wellbore/well components, cleaning equipment, etc., can solve the problems of technical target retention, serious secondary sedimentation, high construction cost, etc., to increase the oil drainage area and prevent clay The effect of migration and avoiding secondary precipitation

CN110886592BActive Publication Date: 2021-12-10CHINA PETROLEUM & CHEM CORP +1
4 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2021-12-10

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a stepwise dissolution and plugging removal method for oil and water wells: (1) injecting pretreatment liquid; injecting cleaning agent; (2) injecting into the main body dissolution system to dissolve different cuttings components in the deep part of the oil and water well; plugging removal radius Above 3.5m; the main corrosion system is selected from the following acid solution plugging removal systems: ①hydrochloric acid system with an acidity of 8% to 12%; ②earth acid system with an acidity of 11% to 16%; ③acidity of 12% to 14% slow acid system; ④ deep penetrating plugging removal acid system with an acidity of 8% to 10%; the injection method of the main corrosion system is gradual injection without flowback; the injection sequence is determined according to the cuttings content; ( 3) Inject protective fluid, no flowback, and the construction is over. The method of the present invention adopts different blocking-removing acid solutions for graded dissolution for different cuttings, which can effectively improve the pore-throat connectivity of the reservoir, improve the water absorption profile of the reservoir and expand the sweeping range of water flooding, and can realize low-porosity and low-permeability storage effective use of layers.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a method for removing plugging by staged dissolution of oil and water wells, which belongs to the plugging removal technology for oil and water wells with low porosity and low permeability. Background technique

[0002] The matrix acidizing of conventional oil and water wells is generally considered to optimize the construction plan according to the type of reservoir rock, acidizing radius, acid dissolution rate, and dissolution time. It is generally believed in the industry that the treatment radius is within 1.5m. In recent years, a series of augmentation injection systems (retarded acid, polyhydric acid, active agent, etc.) The target still stays at the level of dissolved plugs and dissolved rock matrix. During the construction process, the pH value of the acid solution will increase significantly with the advancement of the dissolution radius and the high temperature of the reservoir, resulting in serious secondary precipit...

Examples

Embodiment 1

[0031] Example 1 Oil-water well staged dissolution plugging removal method

[0032] Before construction, first understand the basic situation of the target well, including the following aspects:

[0033] (1) Obtain the reservoir geological parameters and fluid characteristics of the target well, and clarify the sand body distribution law, physical property changes, oil saturation, crude oil viscosity, permeability, produced fluid and other parameters.

[0034] (2) Clarify rock composition, porosity, component content of rock minerals, distribution of natural pore-throats, filling debris composition, and clay mineral composition of different components of gel structure, while clarifying reservoir wettability, oil saturation, sensitivity sex.

[0035] (3) According to the previous production dynamic changes, tests, etc., combined with the production fluid, injection water quality, and pipe string scaling, the type and degree of pollution are determined; and this is used as a re...