Practice and Understanding of Efficient Development of Overseas Complex Intra-Platform Uplift Gasfield: A Case Study of S Gasfield

The S gasfield is a large offshore carbonate gas field crossing two countries. For the characteristics of low reserve implementation, tight capacity construction task and high cost of overseas gasfield development in the study area, this paper applies the thinking of rolling exploration and development, fine gas reservoir description, and confirms reserves and production basis. On this basis, with the core of “fewer wells, higher production and higher gas production rate”, the development and adjustment technologies such as “three-layer combined production, sparse well pattern, vertical and horizontal wells combined, fully using of old wells, refilling potentials, and strengthening reservoir reconstruction” have been implemented. A total of 15 development wells were drilled in the gas field. The productivity of new wells exceeded the pre-drilling design level and increased by more than 40% compared with vertical wells. Reperforating and acidizing treatment increased the production by 3.92 times, and the gas field productivity increased by 142%, taking 18 months to quickly build up to 5 billion m3 gas supply scale. On this basis, an innovative composite boosting production model of “stable low pressure in the early stage, balanced pressure control in the middle stage, and stepwise pressure reduction in the later stage” was proposed, optimizing the timing and production of gas field boosting. The recovery rate of the gas field has reached 72%, and only 4 wells product a small amount of water, which can maintain the daily output of 13 million m3, achieving the development effect of rapid production, efficient development and continuously stable gas supply of the field.