Working solution for removing oil-gas well barite blocking

Abstract

The invention relates to a method for removing oil-gas well barite blocking. The method comprises the first step of allocating a working solution which comprises, by mass concentration, 1-1.2% of nitrilortiacetic acid, 1-1.2% of 4-methyl benzenesulfonic acid pyridine, 0.3-0.8% of 2-butanone sodium alginate, 1-1.5% of sodium chloride, 1-1.2% of poly chlorinated dimethyl diallylamine and 0.1-0.2% of polyacrylamide; the second step of opening a well for gushing, gaining the original capacity and recording the oil pressure observed before blocking removing; the third step of injecting the working solution which is obtained in the first step from an oil pipe and is capable of dispersing and corroding barites under the high pressure, wherein the flow is 2-4m<3> / min, the volume of the added working solution ranges from 200m<3> to 300m<3>, the well closing immersing reaction is carried out for 4 hours, the immersing temperature ranges from 100 DEG C to 160 DEG C, the working solution is injected under the crack opening condition; the fourth step of opening the well for controlling gushing and flowback and gaining the capacity after blocking removing. The method for removing the oil-gas well barite blocking is adopted, the pollution to the immediate vicinity of wellbore from barites is removed after an oil-gas well is drilled and during the process of well repairing by corroding and dispersing the barites, and a target oil-gas layer seepage channel is recovered.

Description

technical field [0001] The invention belongs to the field of energy industry and oil and gas field development, and is used for increasing production of oil and gas wells, in particular to a method for removing barite blockage of oil and gas wells and the adopted working fluid. Background technique [0002] With the in-depth development of offshore and onshore oil and gas field exploration and development, the number of deep wells and ultra-deep wells has increased, and high-density weighting agents are more and more commonly added to drilling fluids. However, the addition of weighting agents increases the solid content of drilling fluids, resulting in Subsidence and intrusion of weighting agent occurred during the drilling process, causing formation solid phase plugging and even seriously affecting oil well production. [0003] Barite is a common solid-phase aggravating material in drilling fluid. Barite is easy to cause damage to the reservoir, mainly reflected in: 1. Seri...

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Problems solved by technology

[0009] The above-mentioned patents do not solve the problem of barite blockage, and are different from the subject of the invention of this application, the technical solutions are different, and the technical effects obtained are different