Effectiveness Analysis of Acid Treatments in UGS Wells

Introduction. In the world practice of using technologies for increasing of production one of the most widely used method for bottom-hole zone treatment for increasing or restoration of wells productivity is acid treatment of productive formation. Acid treatments of productive formation is the essential one in a group of methods for bottom-hole zone treatment directed on maintenance of project well production of gas fields and underground gas storages. Essential aim of acid treatment of gas fields and underground gas storages wells is restoration of reservoir properties in near wellbore zone of productive formation by destruction, transfer to the solution and removing to the bore hole wasting solid particles of natural and technogenic origin, as well as by improvement of filtration characteristics of bottom-hole zone of productive formation by means of expansion of existing and creating of new channels for fluid migration by all length of perforated interval.

Materials and research methods. As the base reagents, used for acid treatment, could be declared hydrochloric (HCl) and hydrofluoric (HF) acids. In the article discussed questions of different factors influence to efficiency of acid treatment. Described mechanism of reaction of acid compound with rock of productive formation, essential principles for choosing of acid compound for terrigenous reservoir.

Research results and their discussion. It is shown analysis of field data about results of acid treatments, done during of workover in wells of one of underground gas storage from 2014 to 2021, information about number of acid treatments, used acid compounds, technological and economic parameters, which allows to estimate efficiency for done activities.

Conclusions. Basing on the results of analysis it is down conclusions about possible directions for increasing efficiency of terrigenous reservoir acid treatments in underground gas storage wells.

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