Utah FORGE is excited to announce the successful completion of the three-stage hydraulic stimulation of its first highly deviated injection well, 16A(78)-32.
Well 16A(78)-32 drilling was completed in January 2021. This is an inclined well (65°to the vertical) that will be the injection arm of the doublet that forms the heart of the Utah FORGE experimental configuration.
Subsequently, two additional monitoring wells – vertical – were drilled so that they, along with existing well 58-32, could serve as monitoring wells for future work at the FORGE site. In particular, wells 58-32, 78B-32 and 56-32 had been instrumented with fiber optics and geophones to triangulate on microseismic events during the recent fracturing in Well 16A(78)-32. These microseismic clouds define the morphology of three hydraulic fractures created at the toe (extremity) of Well 16A(78)-32.
A chronology of the events for the recent three-stage hydraulic fracturing is as follows:
- Fourteen frac tanks were sited on the location and filled with Milford City culinary water. Each tank holds 500 bbl (21,000 gallons per tank) of water.
- Frontier Drilling Rig 28 was trucked to the location, assembled, and brought into service.
- A preliminary run of drill pipe was made into the hole. This drill string had a bit with a casing scraper and a drift sub. The bit was run to near the end of the open-hole section of the wellbore while the casing scraper was positioned to stay within the cased-hole and ensured the absence of debris. The drift sub was run one joint above the casing scraper and guaranteed that there was adequate clearance to run additional tools (in particular, bridge plugs).
- Extreme Wireline next ran a perforating gun on the end of drill pipe into the openhole section (below 10,787 ft MD). In addition to the perforating gun, a mechanical casing collar locator was run and confirmed the casing tally so that the depth of the gun was more accurately known. This 3-1/8” diameter gun was 2 ft long with 6 shots per foot at 60° phasing. MTS Solutions pumped down the drill pipe to seat a dropped ball and fire the guns. The successful firing served as a check shot for orienting geophones in the three offset wells.
- MTS Solutions next pumped a Shear Stimulation Test for one hour at an average rate of 0.36 bpm followed by shutdown and monitoring the pressure decline for an hour. A total of 52 bbl of water was pumped for this test.
- Liberty Oilfield Services next pumped down the casing and followed the prescribed fracturing plan for stimulation Stage 1, reaching an injection rate of 50 bpm with slickwater (refer to Figure 1). 4,261 bbl were pumped. The well was shut in for four hours and flowed back.
- After 16 hours of flowback, Interwell US ran a bridge plug to a depth of 10,670 ft MD (middle of the sealing element). MTS Solutions pumped to set the bridge plug. The bridge plug was tested to 5,000 psi using MTS Solutions’ pumping equipment through the drill pipe and later to over 7,000 psi using Liberty Oilfield Services’ pumping equipment, down the casing.
- After tripping the bridge plug setting tool out of the hole, an Extreme Wireline perforating gun was run into the hole on the end of drill pipe. This was a 20-ft long perforating gun (6 shots per ft, 60° phasing, 21-gram Hero charges). It was run to cover a depth of 10,560 to 10,580 ft MD. MTS Solutions pumped a dropped ball to a seat to fire the guns. The guns were retrieved. All 120 shots had fired, providing an entry from the wellbore to the formation.
- Liberty Oilfield Services next pumped 2,777 bbl of slickwater down the casing and followed the prescribed fracturing plan, reaching an injection rate of 35 bpm. This was Stage 2. There was an intentional hard shutdown in the initial 5 bpm stage and also part way through the 35-bpm stage. The well was shut in and pressure decline was monitored for 4 hours. The well was then opened up and flowed back for 12 hours. The treatment data are shown in Figure 2.
- After flowback, Interwell US ran a second bridge plug to a depth of 10,466 ft MD (center of the sealing element). MTS Solutions pumped to set the bridge plug. The bridge plug was pressure tested to 4,960 psi by MTS Solutions through the drill pipe and later to 6,800 psi using Liberty Oilfield Services pumping equipment, down the casing.
- An Extreme Wireline perforating gun was next run on the end of drill pipe to cover a depth of 10,120 to 10,140 ft MD. This was a 20-ft long perforating gun (6 shots per ft, 60° phasing, 21-gram Hero charges). MTS Solutions pumped to seat a ball and fire the guns. The guns were retrieved. All 120 shots had fired, providing an entry from the wellbore to the formation.
- Liberty Oilfield Services next pumped down the casing for Stage 3 and followed the prescribed fracturing plan, reaching an injection rate of 35 bpm. A slickwater pad was pumped followed by a crosslinked CMHPG fluid with DEEPROP™ microproppant at planned concentrations of 0.5 to 0.75 ppa. The total pumped fluid volume was 3,016 bbl. The well was shut in and flowed back (for more than 15 hr). Refer to Figure 3.
- During the shut-in time, the Liberty frac crew began to rig-down their equipment and demobilize.
- The well was re-entered with drill pipe and an Interwell US retrieving tool to release and recover the second bridge plug that was set. The bridge plug was successfully released and recovered to the surface. After disconnecting and laying down the bridge plug the retrieving tool was run back into the well to recover the first bridge plug that was set. This plug was also successfully retrieved and laid down.
Following the recovery of the bridge plugs from the well, on April 23, 2022 the rig started rig-down operations and laying down drill pipe.