Tertiary Argillaceous Caprock Type And Distribution In Jiyang Depression

Argillaceous rock is the main cover layer. The predecessor to the argillaceous rocks have been extensively studied, mainly concentrated in the argillaceous rocks, rock composition into effect, pore structure, sealing mechanism and so on several aspects, but be crack, fault in the reconstruction of shale rock cover layer was weak research. This paper taking Jiyang depression for third of argillaceous rocks as an example, on the basis of shale rock compression, the springback, rupture experimental material, analysis of crack, fault the shale rock cover layer effects, Based on the cover of the shale rock types and distribution of, and analyses shale rock cover layer and the current have been found (field) distribution of reservoirs relationship. Get the following major knowledge:(1) the evolution of mudstone caprock and its classificationJiyang depression third of argillaceous rocks as depth increases mechanical properties evolution can be divided into three stages:Plastic compaction stage (about0-1000m), Elastic-plastic compression stage (about1000-2000m) and Fracture stage (about2000meters). Cracks are mainly parallel planes, the vertical dimension of joint and inclined seam to seam, cracks can make local destruction of mudstone caprock. Faults can be in to that of mudstone caprock in the larger context of the destruction, in vertical direction can make a plurality of layers of mudstone caprock damage.(2) shale rock cover layer types are classifiedOn the basis of Jiyang depression third series of mudstone caprock evolution characteristics and failure, The mudstone caprock is divided into three categories:Porous cover layer, modified cover layer and broken change slot cover. The porous cover layer is divided into three subclasses:High porosity porous cover layer, pore cap layer with low porosity-ultra low pore cap layer; Off to cover layer is divided into three subclasses:Plastic broken change cover layer, elastic plastic broken change cover layer and crack section off to cover layer.(2) the distribution of mudstone caprock and its relationship with hydrocarbon reservoirJiyang depression third series of mudstone caprock distribution (from shallow to deep). Minghuazhen mainly developed four types of cover layer:In pore cap layer, elastic-plastic break to cover layer, high porosity porous cover layer, plastic broken change cover layer. The Guantao formation in seven types of cover layer: Low porosity and porosity, pore, high porosity, crack, crack section modified elastic-plastic fracture broken change, change, change the cover layer plastic broken. Dongying—sha san shang duan mainly developed seven types of cover layer: Low porosity and porosity, pore, high porosity, crack, crack section modified elastic-plastic fracture broken change, change, change the cover layer plastic broken. The sha san xia duan-sha si shang duan mainly developed five types of cover layer: Low porosity, pore, in joint is changed, change, broken crack section of elastic-plastic break to cover layer.Jiyang depression third series have now discovered oil and gas reservoirs (fields) are mainly located in the seam to cover layer, fault to cover layer and the slit to cover transformation belt, broken change cover layer and the porous cover layer transition belt, sewing and changing cover layer and the porous cover layer transition zone in.