Preparation of recyclable high-density liquid rubber plug and degradation prediction method of recyclable high-density liquid rubber plug

Abstract

The invention provides preparation of a recyclable high-density liquid rubber plug and a degradation prediction method of the recyclable high-density liquid rubber plug, and relates to the field of oil-gas chemical engineering. The recyclable high-density liquid rubber plug is mainly prepared from the following components in percentage by mass through a cross-linking reaction: 30-90% of a weighting agent, 0.01-0.03% of a stabilizer, 0.2-0.6% of a reinforcing material, 1.5-2.0% of a polymer, 0.5-0.6% of a cross-linking agent, and the balance water, wherein the ratio of the polymer to the cross-linking agent is 3: 1. The recyclable high-density liquid rubber plug is prepared from the raw materials, the density is 1.2-1.5 g / cm < 3 >, and the recyclable high-density liquid rubber plug has theadvantages of being good in pumping performance, resistant to temperature, free of rubber breaking, efficient in circulating flowback and the like. Degradation time of different rubber plug systems under different temperature conditions is predicted by establishing a degradation prediction linear regression equation model of the recyclable high-density liquid rubber plug, a flowback process is guided, and safety, effectiveness and smoothness of well completion and workover operation of oil-gas wells are guaranteed.

Description

technical field [0001] The invention relates to the field of oil and gas chemical industry, in particular to a method for preparing a recyclable high-density liquid rubber plug and its degradation prediction method. Background technique [0002] With the continuous increase of deep wells, ultra-deep wells, unconventional, high-temperature and high-pressure oil and gas wells, most wells have problems such as downhole tubing string and wellhead device corrosion damage, tubing scaling, tubing string buckling, deformation and fracture, and workover operations are required. [0003] In most areas, the pressure coefficient is high, and high-density well killing fluid is required for well killing during workover. Conventional organic salt and inorganic salt kill fluids have low density, while barite and iron ore powder aggravated have problems such as poor settlement stability and great damage to the formation. [0004] The temporary plugging and killing plug technology uses the p...

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Problems solved by technology

[0005] However, at present, "liquid rubber stoppers" generally have short slow-down time (a few minutes), difficult pumping (high initial viscosity), or alternate injection of thickener and crosslinking agent, complicated process, and poor high temperature resistance of rubber stoppers. , needs to break the gel, the degradation time cannot be predicted, and the flowback is difficult, especially in field application, which may cause early cross-linking, which makes the pump injection friction high, and even difficult to pump into the target position

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