Declining reservoir pressure, increasing water cuts along with dwindling well counts pose a serious challenge to any mature oil and gas field in sustaining production. In low oil price scenarios, enhancing production using conventional approaches like workover and interventions becomes challenging due to associated costs. This provided an opportunity to look for alternate approaches that are cost-effective and would help to manage these issues on a continuous basis. This paper presents techniques for augmenting productivity of well stock by mitigating a range of issues causing production losses using cost effective, easy to implement chemical based techniques. These techniques have helped the asset to significantly arrest its production decline in the late life phase.

This paper details the approach for identification of issues, selection and field implementation of right chemicals and the benefits that were realized from such applications. Case studies from BG Exploration and Production India Limited (BGEPIL) operated field in Mumbai offshore region are incorporated in this paper to highlight the effectiveness of chemical based approach in mitigating losses right from reservoir to processing platform. Some of the production issues in this mature field which have been successfully resolved using chemical based techniques are:

  • Reservoir:

    • Loss of well stock due to Downhole emulsion issue

  • Well:

    • Calcite Scaling deposition in wells and topsides

    • Liquid loading of High Gas Liquid Ratio wells

  • Pipelines:

    • Back Pressure on wells due to Pipeline size limitation

  • Processing Facilities:

    • Deterioration in Heat Exchanger performance due to fouling

Process adopted includes field data acquisition, analysis using real time state-of-the-art network and process models to identify the root cause of these issues. Results from both steady state and transient models were used to select the appropriate chemicals, conduct field trials / implementation and set the success KPI's accordingly. This paper offers a holistic approach on resolving each of the discussed production issues utilizing the best available technology in the market. Trials and implementation of the various chemicals in the field have added a significant value to the asset; both by protecting and enhancing the current production. More than 20% of current field production is directly attributed to these chemical applications and expected to add more share of production in a far more challenging phase of mature asset.

The approach discussed here for each of such production issues along with the challenges that were faced during implementation will enable other assets to tackle these problems with a more cost effective and easy to implement solutions especially in low oil price environment.

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