Sundance goal: Save time and costs

Sundance wanted to improve surface efficiency and reduce cycle time and associated costs for multistage fracturing in four infill wells while optimizing stimulation designs to avoid depletion effects from existing parent wells.

Analysis of infill well depletion leads to a new idea 

When economics required budget tightening, Sundance asked Schlumberger to review and optimize the stimulation design using Petrel E&P software platform and Kinetix reservoir-centric stimulation-to-production software. After careful analysis of the pattern and extent of depletion caused by parent wells, Schlumberger optimized the stimulation treatment volume in some wells, which maintained production performance while improving well economics by reducing waste.

Still, Sundance believed further improvements in surface efficiency were possible and asked if Schlumberger could perform a dual fracturing operation on a four-well pad.

One frac fleet delivers two simultaneous fracs

Domain experts worked closely with Sundance to design an operation in which two wells could be simultaneously stimulated by one frac fleet to improve surface efficiency and increase the fracture effectiveness between the wells. Overall pumping rates of 120 bbl/min would be split on surface to deliver 60 bbl/min in each well. To encourage fracture propagation at the reduced pump rate, the perforation design was revised.

The StimCommander automated stimulation delivery platform was critical to maximize operational efficiency. StimCommander Process Trailer automated blender and hydration unit enabled different pump schedules for each well and continued pumping in one well even if the other screens out. StimCommander Pumps automated and intelligent rate and pressure control enables pumping on two independent wells with unique pump schedules.

To improve efficiency during rig-up, Schlumberger also deployed virtual wellsite technology that generates a to-scale representation of the wellsite with all the required equipment, enabling better planning for surface operations. Efficient reloading of the enormous proppant silos was crucial, so the layout was optimized to eliminate operational bottlenecks.

Two operations save 10 days and pump more proppant

The four infill wells were stimulated in two simultaneous operations, improving stages per day by 60% and sand pumped per day by 35%. The overall improvement saved 10 days of operations and USD 500,000 in rental, service, and consultant costs as compared with regular zipper frac operations on a four-well pad—and delivered initial production 10 days earlier than usual. In addition, postjob analysis indicates the operations resulted in propagated fractures in about 90% of the perforations, ensuring effective drainage of available hydrocarbons.