Abstract
Raageshwari gas field is located in RJ-ON 90/1 Block in western India with Cairn, Oil & Gas vertical of Vedanta limited as the majority partner and Operator of the field. The field is located in a remote environmentally sensitive region which complicates the gas development project. The reservoir comprises streaks of volcanic sands with low permeability (~0.1 mD). Hydraulic fracturing is required to achieve commercial production from the field. Wells are generally drilled to a measured depth of 3500m and are completed with a 3.5" monobore. There have been 5 fracturing campaigns to date in the field. The previous campaigns were plagued by inefficiencies due to operational, technical, and logistical issues which resulted in cost over-runs. This paper describes the key learnings that were attained and implemented during the last campaign in which ~ 100 fracturing treatments were successfully pumped.
Learnings and observations from the campaign can be placed into four categories:
HSE: Observations made through the campaign which reduced a) the risk in operations, b) waste generation and c) gas flaring (almost no flaring was required in the last campaign).
Operational learnings: Including on-site lessons learnt during the fracturing treatments, post-frac coil tubing cleanout, and post-frac surface well testing. Implementation of these learnings enabled significant completion efficiency gains by the end of the campaign.
Technical learnings: Key elements of the frac design and treatment which resulted in more effective treatments. The percentage of reservoir connected with fractures increased more than 30% which had significant impact on well productivity and estimated ultimate recovery (EUR).
Contractual learnings: Key points that improved contract management and resulted in efficient and smooth running operations.
As a result of implementation of the lessons learnt, days per frac and cost per frac were cut in half. The fracturing campaign was completed ahead of schedule without any LTI incident.
Implementation of these learnings resulted in exceptional improvements in the HSE performance, operational efficiency, and well performance which has significantly improved the economics of this tight gas development project. These learnings are applicable to any non-conventional tight gas development project and are especially important given the current market conditions which require a focus on efficiency and adaptation.
