渤海428构造围斜坡区构造—岩性油气藏成藏规律与勘探潜力分析

Hydrocarbon Accumulation Regulation and Exploration Potential Analysis of Structural-Lithologic Reservoir in Slope Zone of Structure 428, Bohai Basin

近两年来围绕渤海428构造的斜坡区钻探了一批探井,在古近系取得了良好的发现,但是下一步可供钻探的构造圈闭目标十分有限。为了进一步明确该区勘探潜力,从区域—立体勘探的角度,通过对区域构造—沉积演化特征进行综合研究,分析构造演化对沉积类型及其展布范围的控制对油气成藏中所起的作用,在建立区域沉积模式的基础上,明确了该区油气成藏规律。认为古近系东二段以下为一个大型构造—岩性油气藏,油气主要受控于区域泥岩盖层之下储层的发育情况及其展布范围,该模式的建立摆脱了单纯对构造油气藏勘探思维的约束,认为428构造斜坡区应树立构造—岩性油气藏的勘探思路。该成藏模式的建立,大大拓宽了该区域勘探潜力,为该区下一步油气藏整体勘探评价提供了技术支持。

Lots of exploratory wells were drilled around the slope zone of Structure 428 in the past two years, and significant discoveries were made in Paleogene reservoirs. However, the structural trips for next drilling and exploration were very limited. In order to clarify the exploration potential of the area, comprehensive study was done on regional structure-sedimentary evolution features, from the perspective of regional-stereoscopic exploration. The control of structural evolution to sedimentary patterns and their distribution range was analyzed, and its effect on hydrocarbon accumulation was also discussed. On the basis of establishing regional sedimentary patterns, the hydrocarbon reservoir accumulation regulation of the area was clarified. It was believed that a large scale structure-lithologic hydrocarbon reservoir existed under the second member of Paleogene Dongying Formation, and oil and gas was mainly controlled by the development situation and distribution range of reservoirs under regional mudstone cap rock. The establishment of the sedimentary pattern god rid of the constraint of the idea of pure exploration of structural reservoirs. It was proposed that the exploration idea of structural-lithologic reservoir be set for the slope zone of Structure 428. The establishment of hydrocarbon accumulation pattern expanded the exploration potential of the area and provided technical support for next overall exploration evaluation of hydrocarbon reservoirs in the area.