Innovative Surface and Subsurface Solutions to Reduce Emissions and Optimize Production in a Brownfield Offshore Malaysia

Abstract

PETRONAS has set its aspiration to be able to achieve net zero carbon emission by 2050. To achieve this ambitious target, PETRONAS has taken several important decisions with the key one being to gradually cut down on flaring and venting in all fields. This paper will discuss the innovative solutions implemented in a brownfield to optimize oil production while complying with the directive to reduce existing flare by 50% in the field. The operator implemented several innovative and cost-effective initiatives to achieve the objectives: Re-purposing of existing well completions to re-inject and store gas in depleted reservoirs after appropriate Risk Assessment and feasibility studies. Created robust Integrated Network Model to represent the actual field performance at well and reservoir levels and applied it to optimize and re-prioritize well line-up. Optimizing entire field gas compression system considering system constraints, lift, and gas injection requirements. Evaluating alternative artificial lift methods i.e. Thru-Tubing ESP to optimize compressed gas requirements. Evaluating stimulation of Smart water injection wells to maintain reservoir pressure. The operator had excellent preliminary results from the implementation of the above-mentioned steps. Multiple scenarios were run with all the constraints in the updated Integrated Network Model to optimize well line-up sequence to minimize gas production and enhance oil production. Details of the scenarios, gas compressor re-purposing efforts and results will be shared in the paper. The operator also successfully converted idle wells to re-inject gas to store 10 – 20 % of total field emission. Details of the subsurface studies, well completion re-purposing, injectivity tests, risk assessment and results will also be shared in the paper. An artificial lift study indicated that well rates can be increased under the current constraints using the latest Thru-Tubing ESP technology at minimum cost impact. A separate study also indicated that the stimulation of Smart water injectors will increase reservoir pressure to subsequently reduce free gas coming out of solution within reservoir and the ensuing preferential production. Details of both the above studies and implementation plan similarly will be included in the paper. The operator was successful in the challenging task of reducing emission to the limit set by the host authority in line with the PETRONAS carbon emission target aspiration, while ensuring that production was not curtailed because of the emission limit. The paper will describe in detail the afore-mentioned steps taken by the operator which are a landmark achievement in managing a brownfield in the current low carbon environment focus within the oil and gas industry.