Possibility of Increasing the Completeness of Oil and Gas Recovery by Taking Into Account Natural Phenomena in Reservoirs

Abstract

The low completeness of oil and gas recovery when using modern development systems is due to the fact that all development systems are based on the following postulates [1]: 1. There is a hydrodynamic connection within the entire reservoir; the fluid flow in it can be described in terms of Darcy's law. 2. During the reservoir development its filtration parameters are practically unchanged. 3. Hydrodynamic connection is absent between reservoirs in different tectonic blocks. 4. Productive deposits in conventional oil and gas reservoirs are mainly hydrophilic. 5. The properties of fluids in different parts of the reservoir are the same. The properties of residual oil when using water flooding are identical to the properties of the produced oil. Development experience and the results of special studies have shown that these postulates are erroneous. In practice, after establishing the absence of hydrodynamic connection within the entire reservoir, the first priority is to compact well spacing of development wells. In oil reservoirs, additional development wells are drilled predominantly evenly over the reservoir area, that is, almost blindly, without taking into account the large-scale heterogeneity of the reservoirs. In gas reservoirs, additional producing wells are drilled in stagnant zones, which are characterized by increased current formation pressures relative to gas recovery zones. As a result of field and laboratory work, we have identified natural phenomena that determine the fallacy of the above postulates, and it has been practically proven that the internal structure of reservoirs can be identified during their exploration and clarified during development. At the same time, a greater completeness of hydrocarbon recovery and a reduction in the costs of their production are achieved.