New method to shift high-volume, full-bore frac sleeves in a single run
- Well type Producer
- Temperature 133°F
- Pressure 1,088 psi
In late 2017, an operator in Canada needed to reopen high-volume, full-bore frac sleeves after a 48-hour post-frac shut in. These wells are fractured with Coiled Tubing (CT), and the frac sleeves are left in the closed position. Typically, CT will return to the site two days post-frac and reopen all of the frac sleeves. This process reduces the need for post-frac cleanouts.
Using CT for this process, however, carries some risks. Specifically, the mechanical locator used with CT to locate the sleeves can unintentionally manipulate the sleeves a second time, possibly closing them, often leaving operators in the dark about whether or not the sleeve is in fact open or closed. Additionally, it is difficult to identify the sleeve with the locator on CT, because the only method for observation is a weight indicator. The only way to verify the position of the frac sleeve is to pump fluid. Owing to its common use, CT’s risks are accepted, and operators must assume that the sleeves are left in the desired positions after running CT for manipulation.
Welltec® approached the operator with a new solution for shifting open frac sleeves on Wireline (WL) using the Well Tractor®, Well Stroker®, and Well Key®. Welltec’s solution is to use WL to reopen the sleeves, eliminating the need for CT and fluid on location after the frac equipment is rigged out. The operator agreed and allowed Welltec to prove the concept. Ultimately, the goal for the operator is to utilize the Well Stroker and Well Key along with a fiber optic survey to shift the same type of sleeves on injection wells to better manage their water flood program.
For this job, the Well Tractor would provide conveyance in the horizontal part of the well while the Well Stroker and Well Key would open the frac sleeves. In addition, the toolstring included a Casing Collar Locator (CCL) to coordinate depth. The type of frac sleeves used in this well did not include shifting profiles, so the Well Key was configured with high-friction pads. In this case, the Well Tractor conveyed the toolstring past the sleeve to record all assembly signatures. The toolstring depth was then corrected to position the Well Key high-friction pads in the center of the frac sleeve.
After confirming the toolstring’s position, the Well Stroker stroked up to compress the Stroker rod, the key pads were opened, and the Well Stroker then stroked down to shift the sleeve into the open position. Surface Read Out (SRO) data then confirmed whether or not the sleeve had shifted based on the force applied and the length of the Well Stroker. Welltec repeated this method throughout the lateral, shifting open a total of 20 frac sleeves in one run.
This operation demonstrates Welltec’s ability to configure its tools to provide new solutions for complex operations—in this case, using the Well Stroker and Well Key to shift open multicycle, full-bore frac sleeves. During the operation, Welltec’s solution provided proof to the client that the sleeves were shifted. The CCL provided accurate depth control and identified the frac sleeve position—open or closed.
The supplied WL unit and personnel ran on a 24-hour operation schedule and managed to shift open 20 frac sleeves in under 24 hours during one run. The toolstring was run in hole at 8:40 a.m., and the last of the 20 frac sleeves was shifted open at 7:16 a.m. the following day. And, as the operation progressed and more SRO data were acquired, the operation became more efficient, effectively reducing time between sleeves with no tool issues or failures once sleeve shifting commenced.
Welltec’s solution is a step towards a simplified, single-run solution to optimize injection wells for the water flood program.