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在大多数沉积盆地深部通常遇到异常流体压力。自从1970年以来,有效垂直应力和孔隙度之间的关系一直被用于墨西哥湾沿岸地区,评价超压大小。在垂直应力为主的第三系砂泥岩盆地中,根据地震和盆地模拟技术业已取得积极成果,而无论何时压实不平衡条件都发生作用。然而,用该方法不能定量地评价由其它成因和/或附加成因(构造应力、烃类生成、热应力、与断层有关的迁移、水力压裂……)产生的超压。除了传统研究方法外,还提出了流体力学研究方法。在任何深度,上限流体压力受与水力压裂作用或断层复活有关的地层条件的控制。由流体驱动而发生的破裂作用指示存在一个“近于零”的最小有效应力状态下的幕式开放系统。对现今区域构造应力状态的深入理解可以直接判断最小应力的演化。因此,可以对深部流体压力作出定量评价,因为在不排水的或/和封隔的地质系统中,不论流体压力为何种起源,压力将趋于迅速达到接近最小主应力的一个值。因此,超压评价方法将得到改善,因为这一方法可应用于各种不同的地质背景。在这些地质背景中,现今起压起源于其它成因机制,且常常是不同成因机制综合作用。然而,过渡带中的压力趋势很难正确地评价。因而,为了提高可预测性,需要对盖层岩石和断层封堵性进行另外的研究。除了超压评价之外,最小主应力概念便于较好地理解含油气系统,因为与断层有关的烃类动态运移、水力压裂域和盖层岩石封堵效率依赖于超压和最小主应力状态之间随时间推移而发生的微妙的相互作用。
Abnormal fluid pressure is commonly encountered deep in most sedimentary basins. The relationship between effective vertical stress and porosity has been used in the Gulf Coast since 1970 to assess overpressure. In the Tertiary sand-shale basins, which are dominated by vertical stress, positive results have been achieved based on seismic and basin modeling techniques, regardless of when the compaction imbalance conditions are acting. However, with this method it is not possible to quantitatively assess the overpressure created by other causes and / or additional causes (tectonic stress, hydrocarbon generation, thermal stress, fault-related migration, hydraulic fracturing ...). In addition to the traditional research methods, fluid mechanics research methods are also proposed. At any depth, the upper fluid pressure is governed by the formation conditions associated with hydraulic fracturing or fault reactivation. The rupture driven by the fluid indicates the presence of a curtain open system with a minimum effective stress of “near zero.” The deep understanding of tectonic stress state in the present area can directly determine the evolution of the minimum stress. Therefore, a quantitative assessment of deep fluid pressure can be made, since in undrained or / and confined geologic systems the pressure will tend to rapidly reach a value close to the minimum principal stress, regardless of the origin of the fluid pressure. Therefore, overpressure evaluation method will be improved, because this method can be applied to a variety of different geological backgrounds. In these geological settings, the present-day pressures originate from other genetic mechanisms and are often combined with different genetic mechanisms. However, the trend of pressure in the transition zone is difficult to assess correctly. Thus, additional studies of caprock and fault sealing are needed to improve predictability. In addition to overpressure evaluation, the concept of minimum principal stress facilitates a better understanding of petroleum-bearing systems because of the dynamic migration of fault-related hydrocarbons and the efficiency of rock plugging in the hydraulic fractures and cap rocks, which depend on overpressure and minimum principal stress Subtle interactions between states over time.