The Investigation Of Transforming Development Regime For Wa-38 Block By Three Dimensional Physically Scaled Simulation

Steam injection physically scaled model is an effective way to investigate thermalrecovery performance on heavy oil reservoirs. Scaled criteria for steam flooding scaledmodels can be derived by inspectional analysis or dimensional analysis. Recent years,horizontal wells are gaining increased prominence in thermal recovery technologies,wherever, the theories and methods derived from the situations of the conventional verticalwells have been used in domestic physical simulation experiments. Due to the neglect of thecomplexity of fluid flow inside a horizontal well as well as the interaction between the flowinside, and in the vicinity of a horizontal well, the experimental results often show too muchmore optimistic than the practical situations'. Thus one complete set of scaling criteria forsteam injection experiments through high pressure scaled model, including horizontal-well, isgiven by using inspectional analysis in this paper. In addition, both the mechanism for and oilproduction theory of the steam-assisted gravity drainage process (SAGD) are investigated,then the typical dimensionless similarity group for SAGD physical simulation is introduced.For the need of investigation, a large-scale multi-functional high-temperature andhigh-pressure three dimensional scaled physical simulation system, has been devised andmanufactured, which mainly consisted of well pattern model, overlay-pressure system,injection equipment, production facilities, and data acquisition and processing system. Thecritical indexes and parameters designed for each functional system have been given in thistext.The model was used to carry out physically simulated experiments such as conventionalsteam circulation, combined steam circulation, steam flooding and SAGD transformed fromconventional steam circulation, all on the basis of Wa-38 block in LiaoHe oil field.Experimental results show, on the current condition of the reservoir , the conventional steamcirculation can still remain for the next two periods, with total oil recovery nearly 2.07%,andperiodic oil-to-steam ratios from and after the third period may be obviously lower than theeconomical limit value. Both the combined patterns of "injecting and producingsimultaneously" and "one injecting and others producing", compared with the effects ofconventional steam circulation, can improve the temperature distribution and enlarge theamounts of oil possibly forced to move and produced between wells, with total oil recoveryfor the four periods up to 6.81% and 7.87% respectively. In the case of the instantaneousoil-to-steam ratios satisfied with the reasonable economical limits, the oil recovery of thesteam flooding and SAGD transformed from the conventional steam circulation may add upto 31.6% and 46.4% respectively.