Medium-deep well crosslinked polymer gel plugging agent and preparation method thereof

Abstract

The invention relates to a medium-deep well crosslinked polymer gel plugging agent and a preparation method thereof. The plugging agent comprises the raw materials of, by weight, 120 parts of a refined cotton sodium salt solution, 75-85 parts of acrylamide, 13-17 parts of ammonium persulfate, 2-5 parts of cerium sulfate, 4 parts of beta-D-mannuronic acid (M), 1-1.5 parts of ammonium dihydrogen phosphate, 100 parts of composite Portland cement slurry, and 150-200 parts of hybrid microfiber. The water-cement ratio of the composite Portland cement slurry is 0.44. According to the invention, acrylamide, ammonium persulfate and cerium sulfate particles are sequentially added into refined cotton sodium salt solution, such that crosslinked polymer gel is obtained; the beta-D-mannuronic acid (M) is added; the composite Portland cement slurry and the hybrid microfiber are added; the ammonium dihydrogen phosphate is added, and the mixture is well mixed, such that the medium-deep well crosslinked polymer gel plugging agent is obtained. The medium-deep well crosslinked polymer gel plugging agent has high high-temperature resistance and high compressive strength, and is reliable in plugging.

Description

technical field [0001] The invention relates to a crosslinked polymer gel plugging agent for medium and deep wells, and also relates to a preparation method for the crosslinked polymer gel plugging agent for medium and deep wells, belonging to the technical field of petroleum drilling. Background technique [0002] Lost circulation is a technical problem often encountered in the drilling process, especially high-temperature lost circulation will cause a large loss of drilling fluid, leading to an increase in drilling costs, and at the same time, it will cause changes in bottomhole pressure, induce wellbore instability, well collapse, The occurrence of complex accidents such as well kick and blowout seriously restricts the improvement of drilling speed. [0003] At present, when oil drilling encounters a high-temperature formation loss section, due to the lack of high-temperature resistant plugging technology, conventional plugging agents are generally used for plugging. In ...

AI Technical Summary

Problems solved by technology

Although the conventional plugging method has played a role in the plugging project of oil drilling, there are disadvantages or deficiencies at the same time, such as low high temperature resistance, short validity period, poor plugging efficiency, large consumption of plugging materials, long plugging time, and High-temperature deep wells and geothermal wells have a poor plugging safety factor, and downhole complex situations are prone to occur. These shortcomings directly affect the drilling and development process of high-temperature wells and geothermal wells. Therefore, traditional high-temperature plugging materials are far from being able to meet the growing deep and complex wells. Therefore, it is very necessary to study a high-temperature anti-high-temperature plugging agent for high-temperature deep wells.