An overview of chemical enhanced oil recovery and its status in India

India is currently producing crude oil from matured fields because of insufficient discoveries of new fields.Therefore,in order to control the energy crisis in India,enhanced oil recovery(EOR)techniques are required to reduce the import of crude from the OPEC(Organization of the Petroleum Exporting Countries).This review mentions chemical EOR techniques(polymers,surfactants,alkali,nanoparticles,and combined alkali-surfactant-polymer flooding)and operations in India.Chemical EOR methods are one of the most efficient methods for oil displacement.The efficiency is enhanced by interfacial tension(IFT)reduction using surfactants and alkali,and mobility control of injected water is done by adding a polymer to increase the volumetric sweep efficiency.This paper also reviews the current trend of chemical EOR,prospects of chemical EOR in Indian oilfields,the development of chemical EOR in India with their challenges raising with economics,and screening criteria for chemical EOR implementation on the field scale.Furthermore,the review gives a brief idea about chemical EOR implementation in Indian oilfields in future prospects to increase the additional oil recovery from existing depleted fields to reduce the import of crude oil.The outcome of this review depicts all chemical EOR operations and recovery rates both at the laboratory scale and field scale around the country.The additional recovery rates are compared from various chemical EOR methods like conventional chemical flooding methods and conventional chemicals combined with nanoparticles on a laboratory scale.The development of chemical EOR in the past few decades and the EOR policy given by the government of India has been mentioned in this review.The analysis provides an idea about enhanced recovery screening and implementation of chemical EOR methods in existing fields will significantly reduce the energy crisis in India.

Influence of wellhead pressure and water cut in the optimization of oil production from gas lifted wells

The worldwide increase in energy demand necessitates the development and optimization of marginal oil fields for sustenance.In this regard,effective and economic production of fluids are heavily relied upon the artificial lift techniques as the reservoir's natural energy may not be able to deliver the fluids to the surface.Gas lift is a widely practised and successful method that is suitable for rejuvenating the oil production from such fields.In this study,the influence of critical parameters like water cut,wellhead pressure(WHP)and gas-lift gas injection rate on the output from a gas lifted well was analysed.A significant reduction in the oil production was observed with the increase in water cut.For a fixed gas injection rate of 1 Mmscf/day,the production decreased by 26.90%when the water cut increased from 15%to 30%and further by 50.80%when the water cut reached 45%.An increase in the gas injection rate from 1 Mmscf/day to 8 Mmscf/day resulted in an increase in the production rate by 29.21%,40.48%and 56.56%for 15%,30%,and 45%water cut conditions,respectively.It was observed that there is a drop in the oil rate with the increase in WHP for a constant gas injection rate.An increase in the WHP from 100 psi to 300 psi resulted in a drop in the oil production rate by 11.01%,11.78%and 12.74%for 15%,30%and 45%water cut conditions,respectively.The study sheds light on the significance of optimizing the critical parameters to maximize the production from a well,with severely affected productivity,using a continuous gas lift system.