Recently drilled exploration well at Chayandinskoye Gas Condensate Field in East Siberia, where at the moment exploration drilling is at the final stage, was selected as a candidate to evaluate effectiveness of hydraulic fracturing stimulation to boost the production.
During the production logging and the well test on the pilot vertical section, three prolific zones were identified for further development.
As a result of several discussions with the Client and based on the preliminary data analysis, the decision was made to proceed with hydraulic fracturing treatment. Due to the remoteness of the field, unique and complicated geology and reservoir properties, it was clear that the single contactor is required who has a relevant experience and technology being capable to address the challenges and provide an integrated approach. This approach included designing fit-for-purpose well completion, multistage selective hydraulic fracturing and coiled tubing applications inclusive of capability to perform real-time downhole measurements to monitor and evaluate complex multiphase flow profile.
Company's completion segment had introduced and run 168-114mm combined premium-port liner down to 2034m MDDF equipped with 3 ports able to be shifted in open/close position, and hydraulic open-hole swelling packers to isolate annular. This type of completion allows selective or combined production from all the zones. Moreover, it enables selective stimulation of each zone, as well as selective or combined production well testing. In case of water breakthrough, knowing which zone is contributing to the water production, the premium-port can be shift closed to prolong the production without the immediate need to perform costly water shutoff treatment.
Historically hydraulic fracturing has been a very effective way of increasing production in low permeability reservoirs. Based on the job design, three treatments were performed with 39t, 95t and 20t accordingly.
Coiled Tubing services performed debris and residual proppant wellbore cleanout, multiple shifting of premium-ports, nitrogen kick off, and real-time downhole measurements of bottomhole pressure, temperature and production logging.
The remoteness of the gas condensate field and the limited timeframe created additional challenges in terms of logistics, equipment and chemicals mobilization. It was clear that the proper preparation and planning were the key to succeed. Needless to mention that the company state-of-the-art technologies, competent personnel and close collaboration between the segments and the Client were the essential part of the equation.
