Vista Energy wanted to improve the efficiency of multistage fracturing operations in its Vaca Muerta horizontal wells. With four wells per pad and typically up to 40 stages per well, a significant amount of time would have been required to mill out conventional composite frac plugs on CT, which would delay placing the wells on production. Vista Energy wanted to streamline operations to a quick cleanout trip after fracturing.
SLB proposed a high-efficiency plug-and-perf solution comprising a KickStart™ rupture disc valve for the toe stage and ReacXion fully dissolvable frac plugs for the remainder of the wellbore. The KickStart valve is an interventionless technology that initiates fracturing of the toe stage. After the valve opens the well for circulation, the remaining stages are reliably isolated with ReacXion frac plugs delivered simply via conventional pumpdown techniques. The plugs subsequently dissolve without further intervention.
Analysis of the fracturing fluids used by Vista Energy indicated that the freshwater alloy version of ReacXion plugs would deliver optimal dissolution for accelerated cleanout and faster time to production.
On the first well pad, Vista Energy completed 143 frac stages in the four wells in less than 19 days, including 11 stages in a 24-h period, setting a record for the shortest completion time in the region. One contributor to the operational efficiency improvement was the antipreset feature of the ReacXion plugs, which enables rapid pumpdown with consistent setting and isolation performance.
After stimulation, CT was run into the wells for sand cleanout. The shortest time between setting the last plug and running CT was about 4 days, hence the plugs had sufficient time to dissolve. Excellent dissolution performance meant that the cleanout operations tagged only a few plug remnants at the heel stage of the wells.
Following this highly successful first deployment, Vista Energy uses only ReacXion frac plugs for Vaca Muerta fracturing operations and is completing more than eight stages per day on average. SLB has continued to improve the plug design by incorporating a simplified wireline adapter kit and optimized brine-degradable elastomer for these operations.
An estimated 6,000 L [1,585 galUS] of diesel is consumed per day for CT milling operations on these pads. The diesel is used for pumps, injector heads, water treatment, cranes, and other ancillary support. Reducing the time required for cleanout operations equates to less CT operating time, less time on the wellsite, and therefore less diesel consumption. Because 1 L of diesel adds 2.712 kg [0.26 galUS of diesel adds 6 lbm] of CO2e to the atmosphere, the lower diesel consumption significantly reduces CO2e emissions across the well pads.
By exclusively using ReacXion frac plugs for its Vaca Muerta operations, Vista Energy eliminates an estimated 424 metric tons of CO2e emissions per 1,000 plugs deployed. This equated to 222 metric tons of CO2e emissions avoided in 2020 and 361 metric tons in 2021 compared with using conventional composite frac plugs.
