Ailin Jia
Research Institute of Petroleum Exploration and Development, China
Title: Enhancing recovery rate by well pattern infilling for tight sand gas in China
Biography
Biography: Ailin Jia
Abstract
Tight gas plays an important role in natural gas of China. After about 15 years exploration and development, the original reserves and explored reserves of tight gas have been proven to be in large scale. It has fulfilled the beneficially development in Ordos Basin, Sichuan Basin and Songliao Basin, and the total production has exceeded 30 billion cubic meters, accounting for about 1/4 of total natural gas production of China.
In this paper, geological characteristics of China's tight gas reservoirs are systematically analyzed, which are divided into three kinds: multi-layered stacked lenticular reservoir, layered reservoir and massive reservoir. Meanwhile, it`s more complicated for tight gas development in China than that in the United States or in Canada through the comparison of reservoir geological characteristics.
The tight gas development is benefit from engineering and technology based on its own geological characteristics, including high-quality reservoir prediction and well placement optimization, low-cost & fast drilling technology, large well group-multiply well group-factory operating pattern drilling technology, stimulation technology, underground restriction & low pressure transmission, water drainage technique and digital management.
Though tight gas develops fast, it faces with the general problem of low recovery at the same time, with the value just around 35%. Therefore, enhance gas recovery rate has become the key issue now and the future. Taking Sulige gas field, the largest natural gas field in China for example, four kinds of technical methods, reasonable allocation of well production, water drainage technique, old well lateral drilling and well pattern infilling, are introduced to increase gas recovery efficiency. The series of techniques can also provide reference for the same kinds of reservoirs to guarantee stable and beneficial development in the long term.