潜北断层下降盘潭口盐泥隆起塑性变形机制及油气地质意义

江汉盆地潜江凹陷潜北断层下降盘潭口凸起的成因是该区多年关注的问题之一。通过地震剖面解析，认为是由渔洋组—新沟嘴组和荆沙组—潜江组两套多层盐泥侵—底辟刺穿形成的大型盐泥隆起，主要形成于荆河镇组沉积之后，将完整的潜江凹陷分割成3个次洼；盐泥隆的成因是在差异负载和重力滑脱动力作用下潜北断裂下降盘塑性侧向上侵推挤，与上升盘重力滑脱推覆造成南北双向挤压上拱， 形成了以汉水断层面为底板、中部为盐泥隆核、上层盐泥上部膝折—断褶穹窿3层结构；强烈塑性变形使潭口地区潜北断层面中部塑化—揉皱消失， 上部强拱左旋翻转成平卧断层；各个构造层盐泥塑性变形程度和形态差异与构造层盐泥含量、盐泥比有关；盐泥隆是形成各种油藏类型的关键因素，潜三段、潜四上段、新沟嘴组中被盐泥隆和刺穿作用形成的地层、岩性油藏是该区具有勘探潜力的油藏类型，且被近期钻探证实。

The plastic deformation mechanism of Tankou salt mud uplift on the downthrow side of Qianbei fault and petroleum geological significance

The origin of Tankou salient on the downthrow side of Qianbei fault， Qianjiang depression， Jianghan Basin is one of the most attractive problems in this area. Based on the analyses of seismic profiles， it is considered that Tankou is a large scale salt mud uplift which formed by two sets of Yuyang Formatin—Xingouzui Formatin and Jingsha Formation—Qianjiang Formation multilayer salt mud up—diapir penetration， and the main formation stage is after the deposition of Jinghezhen Formation， the complete Qianjiang depression was divided into three sub—depression； The hanging and lower walls of Qianbei fault plastic lateral intruded upward extrusion and decollement—nappe north and south bi—directional compressive upwarp by differential loading and gravitational detachment dynamic effect， forming a three—layer structure： Salt mud uplift with taking the Hanshui fault plane as the base plate， salt mud uplift core in the middle and salt mud kink—faulted dome in the upper； Strong ductile deformation made the middle part of Qianbei fault plasticate—corrugate disappear， the upper segment sinistral turned into flat lying fault； The plastic deformation degree and morphological differences of each structural layers are relevant to the content of salt， gypsum， mud and the ration of salt， gypsum and mud； Salt mud uplift is the key factor in forming all kinds of reservoirs， the layers of the third section of Qianjiang Formation， upper of the fourth section of Qianjiang Formation and Xingouzui Formation lateral sealing by salt mud uplift and diapire， lithologic hydrocarbon reservoir have great potential in oil and gas exploration in this area.