致密气藏水平井液氮伴注压后产能的影响因素

Productivity’s influencing factors of horizontal wells in tight gas reservoir

针对致密气藏储层改造效果不理想、产量低等问题,开展了液氮伴注压后不同因素对水平井产能影响程度的研究。以临兴气田压裂水平井为研究对象,对影响单井产能的地质及工程因素进行计算分析,首先利用主观分析方法中的信息量分析法确定各参数的信息量,然后使用客观分析方法中的灰色关联分析法确定各参数之间的关联度,最后通过对比分析确定各因素的影响程度。结果表明:液氮量、水平段长度、有效厚度、压裂级数是影响水平井单井产能的主要因素;基于2种方法的分析结果整体排列具有一致性,可实现准确快速评价水平井产能,对致密气藏现场生产具有重要的指导和借鉴意义。在临兴气藏后期开发方案设计中,从主要因素中的液氮量为切入点,根据其他影响因素产能的规律来调整参数,可有效提高水平井产能。

Aiming at the problems of unsatisfactory reservoir transformation and low production in tight gas reservoirs,a study on the degree of influence of different factors on the capacity of horizontal wells after liquid nitrogen accompanying pressure injection was carried out.The geological and engineering factors affecting the production capacity of a single well were calculated and analyzed.Firstly,the information quantity of each parameter was determined by using subjective analysis method,information quantity analysis method and objective analysis method.The grey relational analysis method was used to determine the correlation degree between each parameter.The results show that the amount of liquid nitrogen,horizontal section length,effective thickness,and fracture stage are the main factors affecting the single well capacity of horizontal wells.The overall arrangement of the analysis results based on the two methods is consistent and can achieve accurate and rapid evaluation of horizontal well capacity,which is an important guidance and reference for field production of tight gas reservoirs.In the design of the later development plan of the Linxing gas reservoir,the liquid nitrogen quantity among the main factors is the entry point,and the parameters are adjusted according to the pattern of other factors affecting the capacity,which can effectively improve the horizontal well capacity.