This paper will present the development of the combined extreme overbalance perforating (EOBP) and alcoholic retarded acid technique that shows promise of resolving severe formation damage problems that caused by drilling mud leak off especially in abnormal high pressure sandstone gas reservoir with natural fracture. A new alcoholic retarded acid system is presented in this paper that is stable up to 275°F, highly retarded, and significantly less surface tension than straight acid. Laboratory data comparing alcoholic retarded acid with straight acid are shown at temperatures ranging up to 275°F, including core flow tests and Environmental Scanning Electron Microscope (ESEM) observation.

The method was used to remove most of the previously identified skin damage formation of an exploratory gas well in the TARIM Oil Company in TARIM Basin, China. It has proven that it can offer a cost-effective, safe method when used as a near wellbore clean up and maximize the production of gas well. The skin damage had been reduced to 18 from its original 156. The positive effects from using the combined technologies include: Savings in well testing time and cost of additional stimulation jobs to flow the well had traditional procedures been used. A significant increase in the gas production from an original estimated 200,000m3/d to 1,160,000 m3/d. These facts will be evidenced by the case history experiences disclosed in this paper.

You can access this article if you purchase or spend a download.