裂缝性碳酸盐岩底水油藏合理打开程度与合理井距

针对塔河油田S48单元油藏特征,应用油气渗流理论推导出了裂缝性碳酸盐岩底水油藏打开程度与井网密度的匹配关系式.用此关系式可确定该类油藏给定打开程度下的合理井距及给定井网密度下油井的合理打开厚度.研究认为:该类油藏的合理打开程度不宜超过50%,且在打开程度为50%时合理井距最大.开发过程中,随着含水饱和度的增加,合理打开厚度减小;随着垂向渗透率与水平渗透率比值的增加,合理打开厚度增大,合理井距减小.鉴于此,实际生产中应逐段封堵打开井段;实际布井中应根据不同区域的裂缝发育情况,采取不均匀布井方式;在井网的后期加密中应根据已有井的实际参数来确定与之匹配的新井位置和打开厚度.图5表1参15

Rational perforating level and well spacing for fractured carbonate reservoirs with bottom water

For the rational development of Block S48, Tahe Oilfield, which is a fractured carbonate reservoir with bottom water, a correlation equation of its perforating level and well density is derived based on the oil and gas fluid flow mechanics and the oilfield performance. The rational well spacing under certain perforating level and the rational open thickness under certain well density can be determined by this equation. The rational perforating level should be less than 50% and at this value the well spacing is largest. The rational open thickness decreases with the increase of water saturation during the development, and the open well sections should thus be closed gradually in oilfield production. Since the rational open thickness will increase and the rational well spacing will decline correspondingly as the ratio between vertical permeability and horizontal permeability increases, unevenly distributed well pattern should be adopted according to the fracture developments in different areas. In the later period of well pattern thickening, the location of new wells and their perforating thickness should be determined by the actual parameters of existing wells.