济阳坳陷桩海地区下古生界潜山埋藏岩溶作用发育模式

 桩海地区潜山下古生界地层和储层分布具有明显的差异性，随着潜山油气田勘探的深入，这种潜山复杂储集空间的成因成为亟需解决的问题。以往对其储层及孔隙形成的解释，如风化壳成因和大气淡水成因，无法较合理地解释这一现象。研究发现，研究区具有埋藏岩溶作用发生的条件，包裹体均一温度和同位素方面的证据表明研究区存在埋藏岩溶作用且主要为压释水岩溶作用。本文对桩海地区下古生界潜山埋藏岩溶作用模式进行分析研究，归纳出3种模式：倾没端断面补给岩溶模式、翘倾端断面补给岩溶模式和背斜凸起两侧双向入渗岩溶模式。发现研究区下古生界潜山有利储层的分布受埋藏岩溶作用发育模式的控制。压释水首先进入潜山地层的良好储层，而压释水释出地层常形成淀积带，不具备储集条件或成为封堵层。结果表明，很多以前令人困惑的复杂储集空间的成因和下古生界储层和油藏的分布模式可用埋藏岩溶模式进行解释。

The Developmental Modes of Buried Modifications in Lower Paleozoic Buried Hill in Zhuanghai Area of Jiyang Depression

The distribution of strata and reservoirs in the lower Paleozoic buried hill in Zhuanghai area is different in different well fields. The additional explorations of the buried hill are very important to identify the contributing factors of the complex reservoir space. The previous explanations of the reservoir formation, such as by the weathering crust, or those for fresh water of air, can not be applied here properly. The evidences of uniform temperature of inclusions and that of isotopes indicate that there are buried modifications in the studied area, and the main cause of the formation is the press-released water from the Tertiary. Modes of buried modifications are analyzed, and the three kinds of developmental modes of buried modifications are identified: the mode of supplying open-flow in the downward side; the mode of supplying contra-flow in the upward side; and the mode of directed influent supplying contra-flow in the bilateral bulge of anticline. The distribution of favorable reservoirs in the lower Paleozoic buried hill is controlled by the developmental modes of buried modifications. The stratum of the buried hill where the press-released water enters first of all usually is a favorable reservoir. On the other hand, the stratum of the buried hill where the press-released water passes out finally usually becomes a non-reservoir or a plugged zone. The results show that buried modifications can explain the formation of the complex reservoir space and the lower Paleozoic reservoirs and oil distribution models.