静止期未成岩断裂侧向封闭能力评价方法及其应用-《地球科学与环境学报》

文章信息/Info

Title:: Evaluation Method and Application of Fault Lateral Sealing Ability in Quiescent Undiagenetic Period

Author(s):: FU Guang; GE Si; School of Earth Sciences, Northeast Petroleum University, Daqing 163318, Heilongjiang, China

Keywords:: fault lateral sealing ability; quiescent period; undiagenetic; displacement pressure; filler; Dongying Formation; Nanpu sag

摘要:: 为了研究含油气盆地断裂发育区油气分布规律，探讨静止期未成岩断裂侧向封闭机理及影响因素；通过比较断裂断层岩开始压实成岩时间与断裂停止活动时间，确定断裂填充物是否压实成岩；再比较断裂填充物排替压力与油气所在盘储层岩石排替压力的相对大小，建立一套静止期未成岩断裂侧向封闭能力评价方法，并将其应用于渤海湾盆地南堡凹陷5号构造区f1断裂在东营组一段、二段、三段侧向封闭能力评价中。结果表明：f₁断裂在东营组一段、二段、三段填充物排替压力分别为0.70、0.73、0.74 MPa，与之对应的油气所在盘储层岩石排替压力分别为0.19、0.15、0.10 MPa，f1断裂在东营组一段、二段、三段填充物排替压力均大于油气所在盘储层岩石排替压力，断裂侧向上均可封闭，有利于油气的聚集与保存，与目前南堡凹陷5号构造区f₁断裂附近东营组一段、二段、三段已发现油气分布(东营组二段未见油气是因其无圈闭)相吻合，表明该方法用于静止期未成岩断裂侧向封闭能力评价是可行的。

Abstract:: In order to study the distribution law of petroleum in the fault zone of petroliferous basin, the fault lateral sealing mechanism and influencing factors in quiescent undiagenetic period were discussed; by comparing the time at which the fault rock starts compaction and diagenesis with the time at which the fault stops the above activities, it was determined whether or not the fault filler was compacted and diagenetic; then comparing the displacement pressures of fault filler and reservoir rocks located, a set of evaluation method of fault lateral sealing ability in quiescent undiagenetic period was established, and it was applied on the assessment of lateral sealing ability of f₁ fault in Ed₁, Ed₂ and Ed₃ of No.5 tectonic region, Nanpu sag, Bohai Bay Basin. The results show that the displacement pressure of f₁ fault in Ed₁, Ed₂ and Ed₃ are 0.70, 0.73, 0.74 MPa, respectively, and the corresponding displacement pressures of reservoir rock located are 0.19, 0.15, 0.10 MPa, respectively; the formers are larger than the latters, so the fault can be sealed in lateral and is beneficial for the accumulation and preservation of petroleum, which is consistent with the distribution of petroleum discovered in Ed₁, Ed₂ and Ed₃ of No.5 tectonic region, Nanpu sag (there is not petroleum in Ed₂, because there is not trap), indicating that this method is feasible for evaluating the fault lateral sealing ability in quiescent undiagenetic period.