钻井液与完井液2018，Vol.35Issue(2)：131-137,7.DOI:10.3969/j.issn.1001-5620.2018.02.022
考虑接触面积与压差的致密砂岩气藏水相自吸行为
Self-imbibition Behavior of water phase in Tight Sandstones gas reservoir Taking into Account Contact Area and Differential Pressure
摘要
Abstract
During drilling process, water phase invades into reservoirs through capillary force and positive differential pressure, causing water phase trapping in tight sandstone gas reservoirs, and resulting in wrong logging data explanation of pay zones to water zones, hindering timely discovering and accurately appraising of tight sandstone gas reservoirs. To understand the self-imbibition behavior of water phase in tight sandstone gas reservoir, plug cores from a typical tight sandstone gas reservoir were used to simulate self-imbibition by end contact of plug core with water when water comes into contact with reservoir rocks at the moment when the reservoir is first drilled, self-imbibition by soaking of rocks when fractures are flooded with water, and forced imbibition by capillary force under the action of positive differential pressure. The influences of contact area and differential pressure on capillary self-imbibition of water to tight sandstone are analyzed. The simulation test results show that imbibition rate is affected by imbibition area and the development of fracture. The more developed the fractures and the greater the contact area, the higher the imbibition rate, and the imbibition process is easier to reach equilibrium. Positive differential pressure accelerates capillary imbibition in rocks whose physical properties in turn affect the imbibition process. When the physical properties of rocks are low to a certain extent, the imbibition behavior is mainly affected by capillary force. For the dense part of a tight gas reservoir matrix, positive differential pressure has minor effect on imbibition. When fractures are developed in the dense part of the tight gas reservoir matrix, the contact area for flow is increased, and ahigh positive differential pressure enhances the imbibition rate. It is thus concluded that water invasion into tight sandstone reservoirs during drilling and completion can be prevented mainly by plugging fractures and by controlling differential pressure to minimize water-rock contact and the amount of water entering into reservoir rocks.关键词
致密砂岩/裂缝/毛管力/渗吸/正压差/接触面积Key words
Tight sandstone/Fracture/Capillary force/Imbibition/Positive differential pressure/Contact area分类
能源科技引用本文复制引用
李宁,游利军,张震,田键,张绍俊,康毅力,张杜杰..考虑接触面积与压差的致密砂岩气藏水相自吸行为[J].钻井液与完井液,2018,35(2):131-137,7.基金项目
非常规油气层保护四川省青年科技创新研究团队项目(2016TD0016)、国家自然科学基金项目"基于逾渗和固液两相流理论的裂缝性储层工作液漏失损害预测与控制"(51604236). （2016TD0016）
