Title: Production performance of water alternate gas injection techniques for enhanced oil recovery: effect of WAG ratio, number of WAG cycles and the type of injection gas

Authors: Jigar Bhatia; J.P. Srivastava; Abhay Sharma; Jitendra S. Sangwai

Addresses: School of Petroleum Technology, Gandhinagar, 382007, India ' Institute of Reservoir Studies, Oil and Natural Gas Corporation, Ahmedabad, 380005, India ' School of Petroleum Technology, Gandhinagar, 382007, India; Department of Mechanical Engineering, Indian Institute of Technology, Hyderabad, Medak, 502205, India ' School of Petroleum Technology, Gandhinagar, 382007, India; Department of Ocean Engineering, Indian Institute of Technology (IIT), Madras, Chennai, 600036, India

Abstract: Production performance of a water alternate gas injection (WAG) method has been reported for the effect of several operating parameters, such as, WAG injection cycles, viz., single cycle WAG and five-cycle WAG and the tapered WAG at the reservoir conditions of 120°C and 230 kg/cm² for hydrocarbon gas and CO₂ gas. It is observed that the number of cycles in the WAG injection process affects the recovery of oil from the core sample. It is observed that the tapering in the WAG injection process improves the recovery of oil initially in place. The observations on the effect of gases revealed that the CO₂ gas with five-cycle WAG process gives higher incremental recovery than the five cycle WAG process using hydrocarbon gas. It is observed that the saturation profile of CO₂ WAG injection shows the better gas saturation in the core as against the hydrocarbon gas in the WAG process. [Received: April 30, 2013; Accepted: October 7, 2013]

Keywords: enhanced oil recovery; EOR; water alternate gas; WAG injection; gas trapping; tapering; incremental oil recovery; hydrocarbon pore volume; HCPV; production performance; WAG ratio; WAG cycles; injection gas type; saturation profile.

DOI: 10.1504/IJOGCT.2014.059323

International Journal of Oil, Gas and Coal Technology, 2014 Vol.7 No.2, pp.132 - 151

Received: 08 May 2013
Accepted: 07 Oct 2013
Published online: 24 May 2014 *

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