变质岩潜山储集层有效性评价

长期以来，结晶岩基底潜山的储集层有效性评价都是一个有待攻克的地质难题。以渤海湾盆地JZ25-1S变质岩潜山为例，综合利用岩心、薄片、测井、生产测试及实验分析等资料，首先对裂缝特征参数进行了定量描述和表征，同时也从动态和静态两个方面对潜山储集层构成介质（裂缝和基质）的有效性进行了分析与评价。研究表明：区内储集层裂缝发育程度较好，且有效程度高。最有效的裂缝是晚期形成的开启倾斜裂缝，其次是半/充填的垂直裂缝，较差的是早期形成的水平充填裂缝。通过岩石物理特征、生产测井解释及岩心离心实验分析，确立了研究区有效储集层的物性下限；利用静态渗吸实验定量评价了基质动用的开发潜力，明确了毛管力是基质岩块排驱过程的主要驱动力，但影响排驱过程的主要因素是微细裂缝的分布状况和发育程度。

Evaluation of effectiveness of metamorphosed basement buried hill reservoirs

Evaluation of effectiveness of crystalline basement buried hill reservoirs has long been a difficult geological problem.In this paper,JZ25-1S metamorphosed basement buried hill in Bohai Bay Basin is taken as an example.First,fracture characteristic parameters are studied by using various data such as core,thin section,well logging,production test and experimental analysis.Then,the effectiveness of fractures and matrix in the buried hill reservoirs are evaluated based on the analysis of both dynamic data and static data.The research results show that fractures are highly developed in JZ25-1S and their effectiveness is high.The most effective fractures are open oblique fractures which are formed in later period,followed by the half-filled and full-filled vertical fractures,and the worst fractures are the filled horizontal fractures which are formed in early period.With the characteristics of rock physics,PLT and core centrifuge test,the lower limits of physical properties in buried hill reservoirs are determined.By using static imbibition experiment,it is possible to quantitatively evaluate the development potential of Matrix system.Capillary force is the main driving force for drainage process in matrix blocks.And the main factors influencing drainage process are the distribution and growth level of micro-fractures.