Experiment On Improving Sweep Efficiency By Water Injection In Carbonate Reservoir With Multiple Sedimentary Facies In The Middle East

Carbonate reservoirs in the Middle East are rich in reserves,but their sedimentary characteristics are complex and heterogeneity is very strong.These objective factors significantly affect the development effect of super thick carbonate rocks.There are some problems,such as unclear matching relationship between well pattern and multi sedimentary combination characteristics,and insufficient understanding of water drive sweep efficiency of injection production well pattern,which directly affects the design of injection well pattern and the development effect of well pattern.Taking the large plane physical model experiment as the main research means,and integrating the saturation electrode monitoring technology and conventional mercury injection experiment,this paper discusses the influence of well pattern and perforation horizon on water drive sweep efficiency under multiple sedimentary combinations from two different sedimentary combinations,plane and vertical.Finally,the optimized development scheme is verified in the heterogeneous large-scale three-dimensional physical model.The results of plane and longitudinal physical simulation experiments show that the water injection wells are arranged in the low permeability area and the production wells are arranged in the high permeability area,which has better sweep efficiency;In the process of bottom injection combined production,the sweep efficiency of low-speed injection is significantly higher than that of high-speed injection.After the verification of the three-dimensional physical model,the following suggestions are put forward for the actual development of the mine: the water cut rise law of each well is jointly affected by the gravity direction and permeability distribution.It is very easy to cause premature water channeling in the high-permeability area in the extremely thick carbonate rock.On the premise of meeting the injection capacity,the low-speed injection mode should be adopted to select the low-permeability area for injection;The oil production well should be selected in the high permeability area as far as possible to minimize the seepage resistance and ensure the smooth flow of oil and gas into the well.