Research on High-Strength Balanced Plugging Removal System and Process Parameter Design

Temporary plugging acidizing is a critical well stimulation technique for improving water absorption profiles and addressing low/zero water intake in individual intervals of heterogeneous reservoirs, serving as a core measure for production stabilization and enhancement in mature oilfields. However, there remains an urgent demand for balanced stimulation technologies tailored to the unique reservoir conditions of offshore water injection wells. In this study, targeting the reservoir characteristics of the target offshore oilfield, we systematically investigated the effects of Temporary Plugging Agent (TPA) concentration, acid injection slug size, injection rate, and permeability contrast on plugging and diversion performance. Three core innovations are achieved: (1) optimization of a high-strength self-diverting TPA; (2) development of a matched composite retarded acid system; (3) establishment of quantitative process parameter design methods for temporary plugging acidizing in heterogeneous reservoirs. Based on these, a high-strength balanced plugging removal technology for water injection wells was developed. This technology enables balanced stimulation of thin interbeds in offshore water injection wells with large vertical spans, long treatment intervals, and significant variations in reservoir properties and formation pressure, providing robust technical support for optimizing water absorption profiles, achieving precise layer-by-layer stimulation, and enhancing waterflood development efficiency.