Published: 06/29/2015
Published: 06/29/2015
The South-Central Oklahoma Oil Province (SCOOP) is a play that targets the Woodford Shale in Oklahoma, USA. For one operator, plug and perf is the multistage stimulation technique of choice in these cemented horizontal wells. This method is straightforward for every stage except the first because after the casing is cemented, the well is a closed system and perforating guns cannot be pumped down to perforate the first stage.
CT or other mechanical intervention was used to run the perforating guns to the initial toe stage, but this technique increased cost, risk, and logistical complexity. Various toe initiator valves have been available as an alternative to CT for several years, but the operator had avoided their use because many of them are unreliable. The lack of reliability frequently negates their potential benefits because it often necessitates last-minute mobilization of CT units or workover rigs.
Schlumberger proposed use of the award-winning KickStart rupture disc valve to stimulate the first stage. The valve's outstanding record of reliability convinced the operator to use this technology to enhance the efficiency of stimulation operations and save both time and money.
The closed valve is run to the toe of the well as part of the casing string. Casing pressure is then increased to a predetermined value, causing the valve's rupture discs to burst, shifting a sliding sleeve and opening the valve, thereby exposing the formation to the fracturing fluid. The first stimulation treatment can then begin and subsequent pumpdown operations can follow.
The valve performed smoothly as per its design the first time the operator tried it in the SCOOP play. Pleased with the efficiency of the operation and savings in excess of USD 50,000, the company elected to continue its use. 100 installations in less than one year have brought the total savings to USD 5.4 million, with a 100% success rate and zero NPT. The valve continues to form an essential component of this operator's plug-and-perf designs.
Challenge: Improve the efficiency and safety of plug-and-perf operations for multistage fracturing in the Woodford Shale.
Solution: Deploy KickStart rupture disc valve to eliminate the need for coiled tubing (CT) or a workover rig to prepare the toe of the well for the first stimulation stage.
Results: Saved more than USD 50,000/well on average for 100 wells in less than one year, with 100% reliability and zero NPT.
