苏6区块气藏剩余储量评价及提高采收率对策

Evaluation of remaining reserves and strategies of enhanced gas recovery for Su 6 Block

董硕 郭建林 郭智 孟德伟 冀光 程立华

中国石油勘探开发研究院，北京 100083

Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China

针对致密砂岩气藏剩余储量分布及提高采收率对策不明晰的问题，以苏6区块为例，通过气藏精细描述，明确了区块的有效砂体展布特征及气藏剩余储量分布类型，估算了各类型气藏剩余储量占比；基于气藏剩余储量分布特点，应用经济技术指标评价方法，确定了合理的直井井网密度，提出了通过直井井网加密来提高气藏采收率的技术对策。研究结果表明，苏6区块剩余储量分布类型主要为井网未控制型、水平井遗留型、直井遗留型，直井遗留型又可细分为射孔不完善型、复合砂体内部阻流带型2个亚类。其中，井网未控制型为主力剩余气，占总剩余储量的67.7%，为主要挖潜对象。合理的直井井网密度为4口/km2，加密后区块采收率可提高至48%左右。

In view of the problem that the remaining reserves distribution and the measure of improving recovery of tight gas is unclear, taking Su 6 Block as an example, the characteristics of effective sand body distribution in the block were defined through the fine description of gas reservoir, and the distribution types of remaining gas were summarized and the proportion of each type of remaining reserves were estimated. Based on the distribution characteristics of residual reserves, the reasonable density of vertical well pattern was determined by using the evaluation method of economic and technical indexes, and the technical countermeasures of enhanced recovery by infilling vertical well pattern were put forward. The results show that the residual gas distribution in Su 6 Block is mainly divided into three types: uncontrolled well pattern type, horizontal well residual type, and vertical well residual type. The vertical well residual type can be further subdivided into two subtypes: imperfect perforation type and internal choke zone type of composite sand body. Among them, the uncontrolled well pattern is the main residual gas, accounting for 67.7% of the total remaining geological reserves, and is the main potential target. The reasonable vertical well pattern density is 4 wells/km2, and the recovery factor can be increased to about 48%.

10.6056/dkyqt202001015