Release:2016, Vol. 2. №2
About the authors:Andrey T. Tyulkov, Student, Department of Multiphase Systems Mechanics, Institute of Physics and Technology, Tyumen State University; firstname.lastname@example.org
In the recent years, the issues of developing the under-gas-cap zones receive increasing attention. Despite the abundance of scientific and technical literature on the development of oil and gas deposits, the process of development of oil reserves in the under-gas-cap areas remains insufficiently studied. The mechanism of oil displacement from low-productive under-gas-cap zones is not clearly described, as they often contain reserves in small oil-saturated intervals immediately below the gas cap.
This article describes the key issues arising from the development of such deposits and the ways of their solution — in particular, the problem of gas breakout to extractive well cap hole that leads to the inevitable wells, “aeration” and a sharp decrease in oil production. In this connection, a question arises about the cost-effectiveness of the development of under-gas deposits with negligible oil-saturation thickness — oil rims. To resolve this issue, there has relatively recently been proposed a method of gas cap shielding by injecting the polymer solution into the reservoir on the border of gas-oil contact. This method helps to increase the length of the well operation.
The simulation of filtration processes allows to partially study the mechanism of oil extraction from oil rims with isolated gas cap. The simulation was performed on a synthetic simulation model using the “tNavigator” simulator (Rock Flow Dynamics). In this model, the method of shielding gas cap has been realized by injecting a polymeric solution through a horizontal injection well. A comprehensive study of the degree of influence of the main parameters on the development of oil recovery factor has been performed. The optimal operating modes capable of providing the maximum oil recovery factor have been found.