Mechanism research of in-depth fluid diversion by “gel dam” place with horizontal well using X-ray CT

摘要

According to the concept of in-depth fluid diversion by “gel dam” place with horizontal well, its EOR mechanism is studied by means of laboratory water flooding experiment combined with X-ray computer tomography (CT) technique. In the experiment, the artificial cementing heterogeneous model is casted with epoxy resin on surface, and the flooding processes before and after the “gel dam” formed are scanned dynamically by X-ray CT. Through observing the distribution feature of gel dam, tracking the oil and water distribution, water flooding streamline change, oil saturation distribution and its dynamic variation, it is indicated that “gel dam” can effectively shut off the deep channeling in higher permeability layer, and divert the injected water into upper low-permeability layer to displace the remaining oil therein. After “gel dam” is formed, the ultimate oil recovery by water flooding increased by 16.7%, and the water cut ascending velocity slowed down. With “gel dam” technique, gel can be placed in the in-depth reservoir zone to achieve in-depth fluid diversion, which increase the water flooding sweep efficiency and oil recovery. “gel dam” in-deep fluid diversion technique is a promising EOR method for positive rhythm thick reservoirs.