苏里格型致密砂岩气藏水平井长度优化

Optimization on Horizontal Well Length in the Sulige Type Tight Sand Gas Reservoir

水平井是开发致密砂岩气藏的最有效手段之一,水平段长度对水平井的有效泄流面积、动态控制储量以及产能等有直接影响。针对苏里格型致密砂岩气藏有效砂体多呈透镜状、孤立状分散分布的特点,综合静态与动态、地质与开发、技术与经济等因素,从地质评价、理论公式计算、数值模拟分析、经济评价及现场应用效果分析5个方面,建立了致密砂岩气藏水平井长度优化方法。综合评价结果表明:目前经济技术条件下,在苏里格气田采用70型以下钻机钻遇单套有效砂体,合理水平段长度应为1 000～1 200m,有效地指导了苏里格气田水平井的规模化应用。该方法在苏里格气田水平井上的成功应用,为我国其他气区致密气藏水平井长度设计提供了借鉴。

Horizontal well is one of the most effective ways for the development of tight sand gas reservoirs. The parameters, including effective drainage area, dynamic control reserves, productivity and so on, are directly impacted by horizontal well length. Aimed to the geological feature of the lenticular,isolated distribution of the most effective sand bodies in the Sulige type tight sand gas reservoir,integrating the static and dynamic, geological and development, technical and economic factors, rational horizontal well length is derived from five aspects, geological evaluation, theoretical formula calculation, numerical simulation, economi assessment and field application effects. Then the method of optimizing horizontal well length in tight sand gas reservoir is established. The results indicate that the rational horizontal well length of Sulige gas field is 1 000-1 200m while using type 70 rigs and drilling an effective sand body in the current economic and technical conditions. The successful application of the method in the Sulige gas field provides a reference for the design of horizontal well length in tight gas reservoirs of other fields.