Petroliferous Basins Of Sand, Mudstone And Mechanical Properties Evolution Model

Fracturing is one of the most effective measures for oil and gas reservoir stimulation and enhanced oil recovery. Tertiary of the Upper Paleozoic of Ordos Basin and Jiyang Depression, the study area, U.S. Terratek three axial rock mechanics test system, combined with the core observation, thin section analysis, geological analysis and other methods, the above-mentioned areas of sand, shale the mechanical properties of the research division of the extrusion basins and extensional basin sand, mudstone vertical partition of the extrusion basins and extensional basin sandstone and mudstone fracturing countermeasures. Achieved the following understanding:(1) through the rock mechanics experiments, combined with the core observation, analysis and resolution of thin geological method, mechanical properties and mudstones evolution is divided into three stages:1, compaction stage:ordos basin this stage performance in stress for the same condition of shrinkage and mudstones little differences; In jiyang depression the stage, the performance for the stress in the same conditions, shrinkage and mudstones little differences.2and plasticity compression stage:ordos basin this stage performance for in the same stress conditions, the sandstone are coarse compression and rebound, stretch and shrink amount to more than a fine sandstone or mudstone value; In jiyang depression this stage performance in stress for the same conditions, shale rock compression and rebound, stretch and shrink amount to less than the value of the sandstone.3, burst phase:ordos basin for the stage performance after the breaking of crack and mudstones divided into the parallel plane sewing, low Angle oblique seam (with the level of less than45°Angle) and nearly vertical joints (with the level of45°, generally greater than70°); In jiyang depression after the bursting of the stage and mudstones into the cracks of the vertical seam, the parallel plane sewing, oblique sewing, crack combination; Vertical joints is perpendicular to the rock crack development level; The parallel plane is parallel to the rock seam crack development level, and the parallel plane seam can be further categorized into: level seam and sliding seam level; Inclined to crack and rock seam namely oblique development level in combination is divided into:the parallel plane-oblique combination crack, the parallel plane-oblique-vertical combination cracks and parallel planes-vertical cracks combination.(2) extrusion basins and pull a vertical division of the basin and mudstones fracturing of countermeasures. Compaction stage, and mudstones relatively loose, the proposal is not the fracturing. Elastic-plastic compression stage, extrusion and mudstones sexual basin by the principal stress level, mainly produce cracks after fracturing level, it is recommended to end sand-out fracturing technology; Pull a and mudstones basin mainly affected by the stretching zhang, after fracturing mainly for vertical cracks at the end of the recommended sand-out fracturing technology. Burst phase, extrusion basin are natural fracture fracturing, suggested the temporary plugging fracturing techniques, temporary plugging agent under the condition of the horizontal crack temporary plugging calculation formula; Pull a basin are natural fracture fracturing, suggested the temporary plugging fracturing techniques, temporary plugging agent of the vertical cracks under the condition of temporary plugging calculation formula.