Gas production technologies on gas fields at final stage of development

Abstract

About 80% of produced natural gas in Russia is taken from Cenomanian gas deposits of Western Siberia. For a long time, the main volume of gas production was selected on the largest unique deposits in the region - Medvezhye, Urengoyskoye, Yamburgskoye. Currently, the development of Cenomanian deposits of these fields has approached the final stage, and the production of initial balance reserves has exceeded 80 percent threshold. It is known that during gas sampling of more than 80-85%, there is a significant decrease in reservoir pressure, and further extraction of the remaining reserves on condition of their main transportation becomes economically inefficient due to the sharply increasing cost of the extracted products. Residual gas reserves of such deposits are not profitable for production, but with deep compression some of them can be extracted. This part is called “low-pressure gas” in Russian terminology. The assessment has shown that reaching an 85 percent production threshold of balance reserves of Cenomanian deposits, only on Medvezhye, Urengoy and Yamburg fields, there will be at least 1 trillion 700 billion cubic meters of gas, of which more than 600 billion cubic meters is “low-pressure gas”. The experience of cost-effective extraction of such reserves is currently lacking. The high degree of infrastructure development and the importance of socio-economic factors require the introduction of new technical solutions to extend the development and increase the final gas recovery of these fields. Today, within the walls of research and design institutes dealing with the problems of developing Cenomanian gas deposits, the tasks are solved to create new and improve already approved technological approaches for the development of “low-pressure gas” deposits. In this article, an attempt is made to define “low-pressure gas”, to estimate its volumes for currently developed Cenomanian gas deposits of Yamal-Nenets Autonomous District and to give a brief description of proven and promising technical solutions for the well operation at the final stage of development.