OpenPath Reach™ extended-contact stimulation service reduced acid volume by 43% and increased production by 2.3 times. By comparison, prior operations used almost twice as much acid.
An operator in Kazakhstan traditionally stimulated its carbonate wells by fracturing with an emulsified acid system. In some wells, the combination of the acid system with the oil, reservoir rock, and formation water created a stable emulsion. However, the high reservoir temperature required a retarded acid system, limiting the options. For a new well, the operator wanted an acid system that would not create emulsions and would stimulate beyond the near-wellbore area, even if the packer failed.
SLB proposed using OpenPath Reach service, a new single-phase retarded acid system. The single phase significantly improves operational processes, such as mixing and quality control, and stabilizes friction reduction and fluid properties as compared with emulsified and dual-phase acid systems.
During the first operation with the new acid system, a third-party packer failed, and the engineering team had to reduce the pump rate and complete the job as a matrix treatment.
Before the treatment, the well was producing 12 m3/d [75 bbl/d], a rate comparable to offsets before stimulation. Two weeks after treatment, the oil rate was 28 m3/d [176 bbl/d], comparable to a similar offset well treated with the conventional emulsified acid system—but with no sign of emulsions. In addition, the new well stimulation design used 43% less raw acid than the conventional design.
