Research and Application of Horizontal Well Cross-Layer Fracturing Technology in Tight Sandstone Reservoir

摘要

At present,in horizontal well fracturing of tight sandstone reservoirs,artificial fractures can not cross through the mudstone barrier layer vertically and fracturing fluid can pass through mudstone barrier layer,but proppant cannot,which make effective placement of proppant only in sandstone layer at horizontal well section,and reduce the fracturing effect.This paper studied the influencing factors of fracture propagation and extension in tight sandstone reservoirs by laboratory experiments,reservoir evaluation,simulation calculation and field tests.Through comprehensive optimization of fracturing technology,such as fracturing fluid viscosity,construction fluid volume,injection displacement,proppant type and injection mode,artificial fractures can be fractured through mudstone barrier layer and proppant can be effectively propped up in fractures.The results show that the main influencing factors of fracture propagation and extension in tight sandstone reservoir are fracturing fluid viscosity,construction displacement and fluid volume in turn.On this basis,the construction technology was optimized so that artificial fracture can penetrate all thin interbeds of sandstone and mudstone vertically,without causing uncontrolled fracture height,and improving the effective placement of proppant in fractures.The research results were carried out in thin interbedded sandstone reservoirs in Jianghan Basin.The results show that fracturing by this technology can effectively cross through thin interbedded sandstone and mudstone,improve the effective placement of proppant in fractures,and increase the effective reconstruction volume.The stimulation effect was better than the conventional horizontal well fracturing method for the same type of reservoirs,the production was higher and the stable production period was longer.This paper improved the fracturing effect of this kind of reservoir.