A fully soluble bridge plug sealing rubber cartridge and its preparation method and application

Abstract

The invention provides a fully soluble bridge plug sealing rubber cartridge and its preparation method and application. The sealing rubber cartridge contains 30-70 parts of thermoplastic polyurethane elastomer and 70-30 parts of Thermoplastic polyester elastomer. The fully soluble bridge plug sealing rubber cartridge provided by the present invention can be rapidly and completely dissolved in flowback liquid or even clear water when the temperature exceeds a certain value, thereby eliminating the bridge plug drilling and grinding process in the staged fracturing process; In addition, when the sealing rubber cartridge is in use, it can meet the requirement of withstanding a pressure of up to 55 MPa) at a high temperature of up to 93° C. within a certain period of time.

Description

technical field [0001] The invention relates to the technical field of exploitation of unconventional oil and gas resources (such as shale gas, shale oil, tight oil and gas, etc.), in particular to a bridge plug sealing rubber cylinder and its Preparation method and use. Background technique [0002] The shale gas revolution dominated by the United States has greatly rewritten the global energy and strategic landscape. Shale gas has made the United States, the largest oil importer, gradually approach energy self-sufficiency. The price of crude oil has exceeded 100 US dollars per barrel two years ago. One of the admittedly dominant forces in the recent drop to around $50 / barrel has been the massive increase in U.S. shale gas production. According to estimates, the global shale gas resources are about 456×10 12 m 3 , of which the shale gas resources in the United States are close to 30×10 12 m 3 , while the potential resources of shale gas in my country exceed 30×10 12 m...

AI Technical Summary

Problems solved by technology

[0005] Conventional pumping bridge plugs require drilling and grinding, which affects the time and effect of commissioning, and has the following disadvantages and limitations: 1) Oil wells need to be killed, and gas wells need to use coiled tubing or workover equipment under pressure, which is expensive; 2) Construction risks are high , It is difficult to drill and grind the bridge plugs of deep wells and ultra-deep wells; 3) The construction time is long, which affects the flowback of fracturing fluid and production capacity construction, and pollutes the formation

[0007] Publication No. CN105672492 and CN103201453A patents disclose the composition of metal-based soluble bridge plugs, which are soluble in specific electrolyte solutions. In the patent publication CN105672492, it is mentioned that a small amount of ( 3.5%-4.5%) bio-based degradable polylactic acid, but did not explain how to make polylactic acid that is easy to degrade at high temperature and high-melting point copper-aluminum alloy

Moreover, the dissolution of the metal-based soluble bridge plug still needs to inject a specific electrolyte solution downhole, which increases the difficulty and time of the process

[0008] In addition, the sealing rubber cylinder is an important component of the bridge plug. The traditional sealing rubber cylinder uses fully vulcanized insoluble and infusible rubber materials (such as nitrile rubber), so it is not conducive to the dissolution of the bridge plug and cannot meet the requirements of rapid hydrolysis. requirements

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