高邮凹陷真武–曹庄地区戴南组差异富集控制因素

Controlling Factors for Differential Enrichment of Dainan Formation in Zhenwu-Caozhuang Area, Gaoyou Sag

摘要: 目前，高邮凹陷中大多油田都已进入高含水开发阶段，为了尽快寻找接替区块，亟需开展针对已开发区域周边的滚动勘探研究。随着勘探工作的持续深入，科研人员发现研究区前期部署的探井在试采的过程中，戴南组油气的产能表现出较大的差异。为了研究这一现象，本文从圈闭特征、沉积储层以及其他成藏条件出发，运用石油地质学和储层地质学等学科理论，针对真武–曹庄地区戴南组油藏开展差异富集控制因素的分析。结合油气投产初期产能数据分析发现：1) 平均砂体厚度较高的真201断块戴二段投产初期产能较高，而平均砂体厚度较低的曹14断块初期产能也相对较低；2) 真171断块的三条控边断层F19、F17、F20在戴二段的SGR值偏低，真171断块戴二段投产初期产能相较于其周围的真35、真166等断块也普遍偏低。因此认为真武–曹庄地区戴南组沉积相和砂体的展布是导致平面上差异富集的主要原因；而砂体普遍发育的断块之间，断层的封闭情况则是造成差异富集的关键因素，尤其是连接构造高部位的断层，如果封闭性较差，断块中的油气将继续向上运移，导致油气逸散。

Abstract: At present, most of the oilfields in Gaoyou depression have entered the high water cut development stage. In order to find replacement blocks as soon as possible, it is urgent to carry out rolling exploration research around the developed areas. With the continuous deepening of exploration work, the researchers found that the oil and gas production of the exploration wells deployed in the study area showed great differences in the process of trial production. In order to study this phenomenon, based on the trap characteristics, sedimentary reservoirs and other reservoir formation conditions, this paper analyzes the controlling factors of differential reservoir formation of Daian Formation in Zhenwu-Caozhuang area by using the professional theories of various geological disciplines. Based on the analysis of initial production capacity data, it is found that: 1) The E₂d₂ of Zhen 201 fault block with high average sand body thickness has high initial production capacity, while the Cao 14 fault block with low average sand body thickness has relatively low initial production capacity; 2) The SGR values of the three boundary-controlling faults F19, F17 and F20 of Zhen 171 fault block in E₂d₂ are low, and the initial production capacity of Zhen 171 fault block in E₂d₂ is also generally low compared with the surrounding Zhen 35 and Zhen 166 fault blocks. Therefore, it is considered that the distribution of depositional facies and sand bodies of E₂d₂ in the Zhenwu-Caozhuang area is the main reason for the differential enrichment in plane. Among fault blocks with common sand body development, fault sealing is the key factor that causes differential enrichment, especially in faults with high junction structure. If the fault is poorly sealed, oil and gas in the fault block will continue to migrate upward, resulting in hydrocarbon escape.