沁水盆地柿庄北区块水平井开发方式地质适应性分析

Geological adaptability analysis of horizontal well development modein Shizhuang North block,Qinshui Basin

针对柿庄北区块直井表现出达产率低、产量下降快、产能差异大的生产特征,通过对柿庄北区块43口探井、397口开发井进行详细剖析,并与潘河、柿庄南区块地质条件进行了对比分析。结果表明,埋深大、低渗透、煤体结构分布复杂是制约柿庄北区块开发关键地质问题。为了进一步明确柿庄北储层渗透低原因,对柿庄北、潘河、杨家坡区块煤心进行数字岩心扫描,发现柿庄北区块相对潘河、杨家坡区块储层孔裂隙数量都发育最少且孔裂隙连通性最差,并明确煤层演化过程是形成孔裂隙差异的关键因素。此外,结合地质剖析,开展了地质—工程一体化分析,明确直井压裂这种点状开发方式的不适应性,提出水平井开发方式适应埋深增大、煤体结构分布复杂、微观孔裂隙连通性较差的储层特征,并在柿庄北一体化二期显示出较好产气潜力。

In view of the production characteristics of vertical wells in Shizhuang North block,such as low reachability,rapid production decline and large productivity difference,43 exploration wells and 397 development wells in Shizhuang North block were analyzed in detail,and the geological conditions were compared with Panhe and Shizhuang South block.The results show that the key geological problems restricting the development of Shizhuang North block are large buried depth,low permeability and complex coal body structure distribution.In order to further clarify the reason for the low permeability of shizhuangbei North reservoir,digital core scanning was carried out on the block coal cores in Shizhuangbei,Panhe and Yangjiapo.It was found that the develped number of pores and fractures in Shizhuang North block was the least and the connectivity of pores and fractures was the worst compared with Panhe and yangjiapo blocks.It was clear that the evolution process of coal layer was the key factor to form the difference of pores and fractures.In addition,combined with geological analysis,the geological-engineering integration analysis was carried out to clarify that the point development mode of vertical well fracturing was not adaptive,and it was proposed that the horizontal well development mode was suitable for the reservoir characteristics of increased buried depth,complex coal structure distribution and poor connectivity of micro pores and fractures,and showed good gas production potential in the second phase of Shizhuang North integration.