Suspension salt well completion fluid

Abstract

The invention discloses suspension salt well completion fluid, which is a suspension prepared from the following raw materials in percentage by weight: 20 to 82 percent of sodium chloride, 0.5 to 3.0 percent of thickening agent A, 3.0 to 4.5 percent of thickening agent B, 0.10 to 3.0 percent of salt re-crystallization inhibitor, 0.5 to 2.0 percent of corrosion inhibitor, 1.0 to 3.0 percent of fluid loss additive, 0.1 to 1.5 percent of oil layer protecting agent and the balance of water. The suspension salt well completion fluid has the advantages of low damage to a stratum, wide specific gravity adjusting range, high viscosity and low cost.

Description

technical field [0001] The invention relates to a completion fluid used in petroleum exploration and development, in particular to a suspension salt completion fluid. Background technique [0002] At present, in the process of oil exploration and development, with the increasing degree of exploitation and the increase of water injection, as well as the increasing frequency of formation reconstruction operations in production stimulation measures, resulting in Unstable performance of working fluid or workover fluid increases the operation risk. At the same time, due to the high content of insoluble solids in the working fluid, new secondary damage will be introduced when the formation is stimulated, especially in the stimulation measures for low permeability oil and gas reservoirs. , due to factors such as the mismatch and poor compatibility between the conventional killing fluid and the formation, it often leads to operation failure and even affects the normal production of ...

AI Technical Summary

Problems solved by technology

[0002] At present, in the process of oil exploration and development, with the increasing degree of exploitation and the increase of water injection, as well as the increasing frequency of formation reconstruction operations in production stimulation measures, resulting in Unstable performance of working fluid or workover fluid increases the operation risk. At the same time, due to the high content of insoluble solids in the working fluid, new secondary damage will be introduced when the formation is stimulated, especially in the stimulation measures for low permeability oil and gas reservoirs. , due to factors such as the mismatch and poor compatibility between the conventional killing fluid and the formation, it often leads to operation failure and even affects the normal production of oil wells in the later stage; for water injection wells, due to long-term high-pressure water injection, the formation is seriously polluted, resulting The pressure is extremely high. Once a downhole failure occurs, high specific gravity workover fluid or well killing fluid must be used for well killing operations. However, due to the high content of insoluble solids in conventional high specific gravity mud completion fluids, during operation, It will often cause irreversible damage to the formation; the water-soluble salt solid-free completion (workover) fluid is generally composed of formate, chloride salt or bromide salt, and the cost is extremely high, with a specific gravity of 1.6g / cm 3 As the standard, the cost is five times that of this system. At the same time, when the above water-soluble salt completion fluids are used in water injection wells, often due to their low viscosity, water invasion will have a greater impact on the specific gravity of the completion fluid, which is not conducive to Fast on-site operations