鄂尔多斯盆地气藏新类型储层岩石断裂性质及导流能力OACSTPCD

The mineral analysis,cast thin section identification,macro and micro fracture experiments,and proppant embedding tests of Longdong bauxite,Taiyuan limestone and Masi dolomite were carried out in order to determine the mineral characteristics,breaking properties and fracture conductivity of new-type gas reservoir rocks in Ordos Basin.The experimental results show that there is obvious difference of minerals in new-type rocks.The fracture toughness of new-type rocks is higher than conventional sandstone reservoirs,and the fracture toughness of bauxite is related to the content of diaspore.The micro fracture toughness of the new-type rocks is lower than their macro fracture toughness.Branch fractures are easily formed in bauxite and limestone,while the fractures in dolomite are relatively straight.The fracture conductivity decreases quadratically with the embedding depth of proppant.The influence of proppant particle size on the fracture conductivity of bauxite is small under high stress condition.Acidification weakens the mechanical properties of Masi dol-omite,promoting the transformation of proppant from elastic embedding to elastic-plastic embedding,thereby increasing the embedding depth of proppant and reducing the fracture conductivity of Masi dolomite.