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与矿山开采类似,油气开采时,储层和上覆岩层中会产生不均匀变形,从而在上覆岩层中形成压力拱。本文对油气开采时,储层和上覆岩层的变形特征进行了总结,利用现场实例说明了压力拱效应在油气开发过程中的存在性,同时对压力拱的表征参数以及计算方法进行了总结。提出了如果低渗和致密储层忽略压力拱效应,将会夸大应力敏感对储层开发特征的影响,同时导致该类储层开发策略的错误制定。对于该类储层,压力拱将会使得上覆岩层的部分重量传递到外围岩层中,有效地防止储层进一步变形,部分消除应力敏感的影响。压力拱将随着压降漏斗半径的增加而不断地向外扩展,可以增大压降漏斗内外裂缝的导流能力,从而提高油气井的产量和采收率,因此压力拱比较大的低渗致密储层可以适当放大生产压差。
Similar to mine exploitation, during the oil and gas exploration, uneven deformation occurs in the reservoir and the overburden to form a pressure arch in the overburden. This paper summarizes the deformation characteristics of the reservoir and the overburden when oil and gas are exploited, and illustrates the existence of the pressure arch effect in the process of oil and gas development by field examples. At the same time, the characterization parameters and calculation methods of the pressure arch are summarized. It is put forward that if the pressure arch effect is neglected in the low permeability and tight reservoirs, the influence of stress sensitivity on reservoir development characteristics will be exaggerated and the development strategy of such reservoirs will be incorrectly formulated. For such reservoirs, the pressure arch will transfer part of the weight of the overburden to the surrounding rock, effectively preventing further deformation of the reservoir and partially eliminating the effect of stress sensitivity. The pressure arch will continue to expand outward with the increase of the radius of the pressure reducing funnel, which can increase the flow conductivity of the internal and external cracks in the pressure reducing funnel, thereby improving the production and recovery of the oil and gas wells. Therefore, Dense reservoirs can be properly amplified production pressure.