Optimization schemes extraction of inert and acid gases from a trade flow

Abstract

To increase the efficiency of gas-lift method of gas condensate and oil recovery nitrogen can
be used as a natural gas substituting agent. It should be noted at problem actuality because at
“mature” gas-condensate and oil fields high-pressure wells drop in pressure with duration of field
life or there is no sources of high-pressure natural and associated gases at all (eg, oil fields).
When using nitrogen gas as an operating agent for gas-lift operation the possibility of
increasing the volume fraction of nitrogen in natural gas composition grows to maximum at the
production wells wellhead. In these cases it should further pursue the collection and systematization
of natural gas physical and chemical parameters data at the outlet of the gas producing facilities as
the results of necessity of complying with the qualitative indicators for commercial gas transmitted
to pipelines. Operator needs to predict the maximum concentration of nitrogen in the gas
composition after the gas-lift operation for individual wells and define the optimal nitrogen content
and net calorific value of marketable gas feeding to customers. For gathering systems with main
transported product: natural gas artificially enriched with nitrogen for technological operations of   improved condensate or oil recovery, the authors propose to apply a centralized scheme for gas
gathering during production instead of gas gathering at group gas-oil separation plant.
In the article the basic aspects of such schemes, construction of production and processing
equipment for nitrogen removing are represented. The algorithm of nitrogen content calculation,
optimum capacity of nitrogen units are created and prospects for their further use are shown.
The authors argue that the optimization of gas gathering schemes in the fields of
centralization of equipment will save investment and operating costs.