胜利油田罗家地区页岩储层可压性实验评价

Experimental evaluation of crushability of shale reservoirs in Luojia area, Shengli Oilfield

  • 摘要: 页岩储层的"可压性评价",目前国内外尚无统一的评价方法.结合室内岩石力学和物性参数测试结果以及脆性指数计算方法,尝试对目标储层进行可压性评价,探索并形成较为系统的室内实验评价方法.结果显示,页岩抗张强度、单轴抗压强度、抗剪强度和断裂韧性较砂岩和碳酸盐岩低;垂直层理方向粘聚力大于平行层理方向,沉积层理面胶结脆弱;受诱导应力的作用,平行的沉积层理(天然裂缝系)与主裂缝夹角越大,越容易起裂.断裂韧性实验中,当人字形切槽与沉积层理面的夹角在45°以内时,裂缝容易沿层理面扩展;大于45°时,裂缝将穿过层理面扩展.综合分析表明,该页岩储层可压性较强.

     

    Abstract: At present,there is no unified method for crushability evaluation on shale reservoirs at home and abroad.Based on rock mechanics and physical parameter tests in laboratory as well as brittleness index calculations,a systematic evaluation method of laboratory experiment has been proposed.Compared to sandstones and carbonate rocks,the tensile strength,uniaxial compressive strength,shear strength and fracture toughness of shales are lower.Along sedimentary bedding plane,the shear strength of shales is very small and the internal cohesion of vertical bedding is greater than that of parallel bedding.The cementation of sedimentary layer (natural fracture) is very fragile,easily happening shear failure.Under the action of induced stress,the greater the angle between parallel natural fracture and main hydraulic fracture,the easier the fracture initiates.When the included angle between herringbone grooving and sedimentary layer is less than 45°,it is easy to propagate along bedding plane for fractures,but when more than 45°,it can cross the bedding plane.In the end,this shale reservoir is considered to have the conditions of crushability.

     

/

返回文章
返回