Analysis On Block 19-3 Waterflood Pilot In Southern Sag Of Tamtsag Basin (Mongolia)

Generally, reservoir sensitivity analysis and waterflood feasibility study should have been completed before waterflood development in oilfields around the world. According to the laboratory results, the waterflood pilot area will be determined. Systemic and scientific methods have been developed in the world, especially, a whole set of research technologies have been developed to guide oilfield develoment.Based on the characteristics of geologic structures and formation development of southern Tamtsag Basin in Mongolia, a series of laboratory experiments have been completed, including reservoir sensitivity analysis, numerical simulation, evaluation on well completion fluid, flood water, clay inhibitor, water/oil displacement, etc. Aiming at solving the problem of strong water sensitivity in Block 19-3, a research on evaluating the performance of clay inhibitors has been performed and the ideal clay inhibitor which is able to effectively inhibit clay expansion has been chosen. On the basis of laboratory experiments, the well group 19-14 has been chosen to be the pilot area of waterflood pilot which takes peripheral flooding and inside scattered flooding as its flood pattern.In this paper, well performance of well group 19-14 has been analyzed and the effect of reservoir sensitivity on waterflood development has been evaluated; taking the geologic characteristics and the effect of oilfield development in the pilot area into consideration, the feasibility of the current pattern well spacing and flood pattern has been evaluated; the appropriate drawdown pressure and suitable waterflood timing have been determined; numerical simulation has been completed according to the laboratory experiments and field test, and consequently, appropriate well pattern, well spacing and waterflood pattern have been established; the feasibility assessment of waterflood development in well group 19-14 and in Southern Sag of Tamtsag Basin has been carried out, which provides reliable information for developing Tamtsag Oilfield sustainably, effectively and economically.