新场气田上沙气藏压裂开发评井选层研究

RESEARCH ON WELL EVALUATION AND FORMATION CHOOSING IN DEVELOPMENT OF LOW PERMEABILITY SAND RESERVOIRS IN XINCHANG GAS FIELD

压裂是低渗砂岩气藏开发的主要手段之一,而低渗砂岩气藏复杂的地质特性、平面及纵向上的非均质性造成相当一部分气井压后产能低,增产效果差。压裂开发前如何进行合理的评井选层,往往是压裂增产成败的一个关键因素。新场气田Js21气藏难动用储量比例大,III类储量占79.2%,目前主要以压裂开发为主。通过对气井压后产能及影响因素的评价与分析,认为储量级别、储层物性、构造位置等参数是压裂开发中评井选层的主要决定因素,从而提出了新场气田Js21气藏有针对性的压裂开发评井选层原则,在目前工艺条件下,当储能系数(HSg)大于0.63,地层系数(KH)大于1.90×10-3μm2.m,气井压裂后能获得较好的工业产能。

Fracturing is one of effective developing method for low permeability sandstone reservoirs.But complicated geologic characteristic and heterogeneity make many fracturing wells low off-take potential after fracturing.How to evaluate and select fracturing wells and layers rightly is a key to insure successful fracturing.In this paper,based on the features of Js12 reservoir in Xinchang gas field,the influence of fracturing on production was analyzed,and the methods on evaluating and selecting fracturing wells and layers were studied,and the principle of formation evaluation & well choosing was put forward.When reserve energy coefficient(HφSg) is over 0.63 and permeability capacity(KH) is over 1.90×10-3 μm2·m,the good off-take potential could be obtained after gas well fracturing.