Tartan Cemented MultiFrac Limited Entry Ball-Drop Systems
Increase Production by 12.5% in the Utica
A major operator exploiting the Utica shale formation wanted to maximize stimulated rock volume on their most extended reach horizontal wells. They were lo o k i ng for a cemented completion solution that would enable more frac stages while simultaneously increasing limited entry cluster efficiency. They were using cemented plug-and-perf completions, but wanted to take advantage of the more time-efficient operation of ball-drop sleeves, while maintaining cemented liner
Tartan proposed a solution that allowed the operator to increase their stage density while optimizing cluster efficiency. The patented MultiFrac™ sleeve enables simultaneous stimulation of multiple stages with one actuation ball. The integrated patent-pending BurstPoint™ port technology increases cluster efficiency from 55% to 95% by preventing proppant erosion during the fracturing treatment – translating to increased production. The BurstPoint ports are machined such that they explosively open at a known threshold pressure and are sized to match the limited entry design (Fig. 1). Until the point of fracture initiation, the BurstPoint ports remain totally closed preventing cement from entering the system, enabling reliable ball-drop operations.
The operator chose to complete 4 wells, 2 wells on each of two separate pads with hybrid cemented systems using Tartan’s MultiFrac for 18 treatment stages at the toe comprising 5 MultiFrac sleeves (clusters) for a total of 90 sleeves – the most cemented ball-drop sleeves ever run – and a further 16 plug-and-perf stages at the heel.
All 360 MultiFrac sleeves successfully functioned with clear pressure signatures for sleeve shifting and opening of the BurstPoint ports (Fig. 2). On average, each stage was pumped at 80 bbl/min with 5,100 bbl of fluid and 330,000 lb of proppant for a total of 5.6 million lb per well (see job summary). On average, the 18 MultiFrac treatment stages were stimulated in 1.5 days compared to 3 days for the 16 stages of plug-and-perf.
In addition, calculated limited entry back pressure is maintained throughout the stage treatment with BurstPoint ports (Fig. 3) compared with plug-and-perf (Fig. 4) because they are not affected by proppant erosion.
Reviewing production between two wells completed with the MultiFrac system on 18 of the 34 stages verses two wells on the same pad with 34 stages of plug-andperf for the first 180 days showed a 12.5% increase for the well completed with MultiFrac systems (Fig. 5). If MultiFrac sleeves were used on all treatment stages, by extrapolation this increase would have been 23.7%.