Double protection type perforation fluid

Abstract

The present invention discloses a double protection type perforation fluid, which comprises the following components, by mass, 100 parts of water, 0.2-0.5 part of a tackifier, 0.8-2 parts of a filtrate reducer, 2-3 parts of an anti-swelling agent, 0.05-0.15 part of a surface active agent and 0.05-0.2 part of a gel breaker. The double protection type perforation fluid has the following characteristics that: the double protection type perforation fluid has a certain viscosity so as to provide good effects of cleaning and chip carrying while ensure pumping; filter loss is low so as to minimize damage on stratum by the filtrate; anti-swelling rate is high so as to inhibit clay hydration expansion; interfacial tension is low so as to facilitate fluid flowback and reduce water blocking damage; with automatic polymer degradation and gel breaker application, damage caused by polymer adsorption are eliminated; and core permeability recovery rate is high, and a good protection effect is provided for the oil layer so as to solve problems of damage on the stratum and environment pollution caused by stratum pore channel surface absorption of high molecular polymers in the polymer perforation fluid polymer.

Description

technical field [0001] The invention relates to a perforating fluid, in particular to a perforating fluid which can not only protect the oil layer but also protect the environment in the process of petroleum exploration and development. Background technique [0002] Reservoir damage occurs in every link of exploration and development, among which perforation completion is an important completion method in onshore oilfields, and a certain degree of damage is inevitable in the process of perforation testing. In the perforation and completion operation, the quality of the perforating fluid is directly related to the productivity of the oil and gas well. Improper selection of the perforating fluid will lead to the failure of the measures to protect the oil layer during the drilling process and cause serious damage to the development. [0003] At present, the perforating fluid systems in various oilfields mainly include five types: solid-free clean brine, polymer, oil-based, acid...

AI Technical Summary

Problems solved by technology

Oil-based, acid-based and emulsion perforating fluids have not been used on a large scale due to their high prices. The most practical application is solid-free clean brine perforating fluid. Although this type of perforating fluid has no harm from adding solid phase, the price Relatively cheap, but its low viscosity, poor ability to carry debris, weak ability to clean blastholes, high fluid loss, easy to emulsify with crude oil when entering oil layers, easy to cause water lock damage when entering low-permeability layers, short time for inorganic salts to stabilize clay, and cannot prevent follow-up Water-sensitive damage of the operation, and not suitable for oil reservoirs with serious leakage

Polymer perforating fluid overcomes some shortcomings of solid-free clean brine perforating fluid, but the current polymer perforating fluid does not consider that the polymer itself will cause certain damage when adsorbed on the surface of the formation seepage channel, so a way should be found to be lifted; neither considered the impact on the environment

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