UTILIZATION OF A CRYSTALLIZED HYDRATING COPOLYMER TO MODIFY AN INJECTIVITY PROBLEM IN A HORIZONTAL CO_2 WAG INJECTOR IN THE SOUTH COWDEN UNIT, ECTOR COUNTY, TEXAS - POST TREATMENT COIL TUBING ACIDIZING STIMULATION - CASE HISTORY

摘要

An open-hole completed lateral CO_2 WAG injection well in the San Andres formation had not performed as desired in developing a sweep of upper structure pay and indications were that an injection profile problem existed. It was ascertained that all injection fluids were entering into a known 30-40 ft. interval approximately 230 ft from the toe of this 1,337-ft horizontal lateral rendering the remaining lateral section ineffective. Tracer surveys and interference pressure tests showed most injection fluids were being lost out of the productive interval and not giving the desired response to offset producers. A conformance design utilizing a dehydrated crystallized copolymer was implemented to control the loss of injection fluids into the unwanted zone. With confirmation of a positive treatment response, a coil tubing stimulation utilizing 135℉heated acid was performed to improve injectivity into the desired intervals within the remaining lateral section.