侧钻水平井可动用原井控制储量,挖潜侧向、纵向剩余油气藏。国内外研究表明：长时间停产井重新复产及低产井增产都需要实施侧钻水平井工艺。苏里格气田地处鄂尔多斯盆地,是我国储量规模超万亿的特大气田,已建成249×10⁸ m³的年产能,但其单井产量低、递减速度快,日产量小于3 000 m³的井占50 %。如何实现苏里格气田开发的稳产和降本增效,探索侧钻水平井,提高气田采收率是一个技术方向。针对研究区块的小井眼侧钻水平井的工艺难点,从安全钻井、完井工艺、经济效益方面开展研究。现场试验侧钻水平井12口,平均水平段长度672 m,平均钻井周期为49 d,工艺实施后平均单井日产气量2.7×10⁴ m³。实践表明,套管侧钻水平井对苏里格气田低产低效井提高气田采收率在技术上是可行的。

Sidetracking horizontal wells can be used to control reserves, digging potentials and longitudinal residual oil and gas reservoirs. The researches at home and broad show that both restart production of long-time shutdown wells and increasing oil and gas production in low production wells need to imply sidetracking horizontal wells. The Sulige Gas Field, located in the Ordos Basin, is a giant gas field with reserves exceeded trillion, and in there an annual production capacity of 249×10⁸ m³ has been built. However, its single well yield is low, the rate of decline is fast, and the number of wells with daily production less than 3 000 m³ accounts for 50 %. To explore side drilling horizontal wells and to improve gas recovery are the technical directions to achieve the steady production, cost reduction and efficiency increase in development of Sulige Gas Field. In view of the difficulties of sidetracking horizontal wells with small holes in the research block, the researches are carried out on safe drilling, completion technology and economic benefit. Twelve sidetracking horizontal wells are tested in site, with an average horizontal segment length of 672 m and an average drilling cycle of 49 d. The initial average daily gas production of a single well after sidetracking was 2.7×10⁴ m³. The practice shows that it is technically feasible for the casing sidetracking horizontal well to improve gas recovery of low production and low efficiency wells in Sulige Gas Field.