Sandstone Reservoir Pore Formation And Plugging Of The Stochastic Simulation

Unconsolidated sandstone reservoirs are all over international various oil region .Consolidation degree of rock is weak, the shale content is high, massive clay particle adsorbed in the pore surface is being extremely easily carried away during oil mobile process, the clay meeting water is easily inflated, hydrated, dispersed, and migrated after water flooding.Therefore, the formation structure of unconsolidated sandstone reservoirs has changed distinctly after the long-term high speed water-flooding, The effects of injected water to pore structure, rock skeleton granule, bond and reservoir fluids, and the changes of reservoir temperature and pressure, make formation permeability increase, pore throat radius increase, thus high permeability or terribly high permeability zones are come into being in reservoir, namely water channel.In reservoirs exists water channels, injected water cyclically produced inefficiently along water channels, so that the utilization efficiency of the injected water is lower, meanwhile the pore volume swept by water driving is reduced, and the improvement of oil recovery and development benefit is seriously affected. Moreover, development of the fields once enters high water cut stage, water channels make stimulation measures more difficultly. for instance it can cause the polymer solution cyclically produced inefficiently, and form the high grade polymer plug with difficulty in formation, seriously affected the polymer's effect.Therefore, strengthens to research on formation mechanism, recognition and description of water channels, and forecast its size and distribution, and further mechanism research for profile control/water shutoff, description the migration of agent to profile control/water shutoff by stochastic simulation, it is guiding significance to optimize polymerized substance and profile control agent volume , intensity , slug arrangement grade , and it has the important practical significance toward water shutoff/profile modification , sublimation reservoir swept volume and/or oil recovery factor.the vital significance of strengthens to study on water channels lies in not only the instruction development for unconsolidated sandstone reservoirs at high water cut stage, but also the good instruction function for the conventional sandstone reservoirs water-flooding development at mid and late part stage, and the dynamic monitor technology such as well test, well logging and so on for sandstone reservoirs at low water cut stage, and sand control.On formation mechanism, the recognition and plugging up technical for water channel of unconsolidated sandstone reservoirs, the predecessor has done the massive research work, and obtained the certain research results. But these research results are far not satisfied to water-flooding development need in unconsolidated sandstone reservoirs at mid and high water cut stage.Along with water-flooding development thorough, as a result of the hydrodynamics geology function, make the formation characteristic change unceasingly, and the water channels intensified the changes more complexity. How effectively distinguishes water channels, determined water channels size, position distribution, how well did know mechanism of water channel, it is a urgently topic needing to solve.