Abstract
System analysis is required to produce a development program for an oil and gas field which is a system formed of reservoir, production string, flow restrictions, flow lines and surface facilities. System analysis technique was applied to an oil field in Kazakstan in order to determine the efficient system for the field and to produce a development program. To model the components of the systems commercial softwares were used. The study was commenced with the analysis of data on the reservoir and production as input to the models. The models were tuned through history matching by modifying fluid properties of oil, and basic reservoir description parameters. Following the history match, performances of production strings of different sizes, with and without artificial lifting were compared to determine the most efficient production string for the field.
The analysis verifies that considering the components of an oil and gas production system individually may result in performances lower than optimum. To search for the best development scheme, the production system must considered as a whole. It was determined that all the wells of SSTA, first reservoir unit, should be produced by making use of 2 7/8 in. tubing size, 100 stage D-12 pumps for wells W-77, W-95 and W-110, and 100 stage D-20 pumps for W-79 and W-111. For the other reservoir unit, SST5, use of 2 3/8 in. tubing with 100 stage D-20 pump was advantageous for W-98 and W-Y3, while use of 3 1/2 in. tubing with 200 stage D-12 pump was advantageous for W-116 and W-117.
Finally in the study, development program was formed for the field using the mentioned string-artificial lift combinations. In the end, 517,068 m3 oil was produced from SSTA which corresponds to 42.7% of OOIP with no injection and new production wells. 738,956 m3 of oil was produced from SST5 which corresponds to 27.1% of the OOIP by injecting 1,375,000 m3 water and operating two new production wells.
