Separate layer fracturing and multi-layer production of tight sandstone gas reservoirs in the Sulige Gas Field, Ordos Basin: Problems and countermeasures
Li Xianwen, Xiao Yuanxiang, Chen Baochun, Shen Yunbo, Wen Xiaoyong, Zhou Changjing, Shi Hua & Jin Fuguang
(1. National Engineering Laboratory of Low-Permeability Oil & Gas Exploration and Development, Xi'an, Shaanxi 710018, China; 2. Oil and Gas Technology Institute, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China; 3. Development Department, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China)
In the Sulige Gas Field of the Ordos Basin, many sets of gas-bearing strata are developed, such as Permian Shanxi Formation and Shihezi Formation, and they are typical tight sandstone gas reservoirs with the characteristics of multiple layers in one well, low single-layer production, strong lateral heterogeneity, low permeability, low pressure and low abundance. After years' exploration and development, the geological conditions in the Sulige Gas Field are understood better and better, and the innovative development of processes and technologies and the continuous improvement of technical ideas promote scale production. With the continuous advance of exploration and development, however, the reservoir conditions become more complex, which brings new challenges to the efficiency increase and cost reduction of separate layer fracturing and multi-layer production technology. In this paper, the development history of separate layer fracturing and multi-layer continuous production technology in the Sulige Gas Field was reviewed, and the understandings and enlightenments obtained from the researches were analyzed and summarized. It is indicated that the existing separate layer fracturing technology consisting of two main parts (i.e., mechanical packer and casing sliding sleeve) is the key technology for the economic and efficient development of the Sulige Gas Field. It doubles the efficiency of fracturing operation, presenting a good application effect. Then, the technical challenges facing the Sulige Gas Field during its development were summarized as follows. Multi-layer production is insufficient, the drilling technologies cannot guarantee the benefit development in the whole life cycle of gas wells, and the separate layer fracturing technology can hardly give considerations to the congruent development of Upper Paleozoic and Lower Paleozoic. Finally, combined with the development situations of Sulige Gas Field, the countermeasures to above mentioned difficulties and the development direction of the separate layer fracturing and multi-layer production technology suitable for gas reservoirs were discussed as follows. First, strengthen the researches on well pattern matching and improve the reserves producing degree and the ultimate recovery factor. Second, select the layers to be transformed, optimize the separate layer fracturing technology, and improve the development benefit of multi-layer production. Third, optimize drilling and production technologies systematically, and establish a new efficiency increase and cost reduction model for the whole life cycle of slim holes. Fourth, research the separate layer fracturing and commingled production technology suitable for Upper and Lower Paleozoic reservoirs, so as to satisfy the congruent development of Upper and Lower Paleozoic gas reservoirs.
李宪文,肖元相,陈宝春,沈云波,问晓勇,周长静,史华,靳福广. 苏里格气田致密砂岩气藏多层分压开采面临的难题及对策[J]. 天然气工业, 2019, 39(8): 66-73.
Li Xianwen, Xiao Yuanxiang, Chen Baochun, Shen Yunbo, Wen Xiaoyong, Zhou Changjing, Shi Hua & Jin Fuguang. Separate layer fracturing and multi-layer production of tight sandstone gas reservoirs in the Sulige Gas Field, Ordos Basin: Problems and countermeasures. NATURAL GAS INDUSTRY, 2019, 39(8): 66-73.