Features of bottomhole zone treatment and formation stimulation by large volumes of hydrochloric solutions

Abstract

The study confirms the hypotheses on the impact of the injection rate and the specific flow rate of the acid composition on the efficiency of treatments. Factors that increase the risk of inefficient measures were identified: fracture pressure excess during the implementation of the technology significantly increases the risk of water flooding of a well after treatment; energy state of the formation – level of formation pressure at targeted development is below 40% of the initial state; presence of active water-saturated feed zones that support formation energy during development, but increase the risk of water breakthrough. The following changes to the technology were proposed to increase the efficiency of carbonate reservoir treatment: when calculating the planned volumes of the acid composition to use specific parameters depending on the length of the treated interval or perforated thickness; acid composition is injected at the maximum possible specific flow rate (at least 1.8 m3/h per meter) without exceeding the fracture pressure; to reduce the minimum permissible level for large-volume acid treatments of formation pressure from 60 to 40% of the initial level.