【摘要】 本文论述了英台地区源近流短、沉积速度大所导致的压实与排水不平衡;随地热梯度的增高,蒙脱石脱水转化提高维持压实与排水不平衡所需的排水速度和水热增压引起泥岩中颗粒、孔隙水体积膨胀提高孔隙流体压力等作用,是控制本区泥岩异常高压带形成和分布的三种成因机理。泥岩异常高压、构造变动和泥岩同生收缩,是致使泥岩裂缝发育的原因和控制裂缝展布的基本因素。泥岩异常高压带的形成,不仅使泥岩与邻近的储层、输导层孔隙流体间产生过剩的流体压力差,而且还导致泥岩裂隙发育地段的形成。一方面为石油初次运移提供了必要源动力,另一方面也为石油赋存提供空间,故此对泥岩裂缝油气藏的形成起着重要作用。更多还原

【Abstract】 This paper suggests that 3 factors govern the formation and distribution of the abnormal pressure belts in Yingtai area,i.e.: (1) the inequilibrium between the compaction of the shale and the drain- age of the formation water due to the short flow channels; (2) the dehydration of the montmorillonite under relatively high temper- ature due to geothermal gradient resulting in a higher requirement for water drainage;and (3) the expansion of water and the shale grains due to the relationly high formation temperature resulting in an increase of pore pressure,hydrothe- rmal effect. The abnormally high pressure in the shales,the tectonic movements and contemporaneous contraction of the shale are the main factors resulting in the development of the fractured shales and governing their distribution. The formation of the abnormally high pressure zones in the shales not only produce excessive pore pressure differences between the shales,and their adj- acent reservoirs and migration formations,but also results in the formation of the fracture systems in the shales.This process gives the power for the pri- mary migration of pil and gas.Meanwhile,fractured shales contribute space for the accumulation of oil and gas.Thus,it plays an important role in the formation of fractured shale oil and gas reservoirs.更多还原