Increasing water prodn. rate of wells

摘要

Water discharge from drilled wells increased by introducing into the filter section of the well a weak acid of dissociation constant below 0.001. After a period of 10-48 hr, with the well under pressure, the well is flushed using a scavenging pump. A soln. of NaHCO3 and/or NACL is then introduced into the filter and after a further period of 1-36 hr. the well is again flushed using the scavenging pump. Pref. acids are acetic, tartaric, citric or metaboric and/or tetraboric acid. - The method can be applied to old wells and to newer wells in which mud has collected. The treatment increases the permeability of the rock formation and avoids the problems (corrosion and layer collapse) associated with use of hydrochloric acid. USAB- US4541488 A Water discharge of a drilled well previously used for water delivery and having decreased water discharge, is increased by (a) introducing a weak acid of dissociation constant less than K(D) = 0.001 for 10-48 hrs. under pressure into a filter section of the well; (b) flushing the filter section using a scavenging pump to remove acid; (c) introducing basic sodium bicarbonate and/or -hypochlorite soln. into filter sections for 1-36 hrs.; and (d) flushing the filter section as in (b) to remove basic soln. - Pref. acid comprises acetic-, tartaric-, or citric acid; or metaboric and/or tetraboric acid.