Effectively stimulate the well regardless of water quality, proppant volume, or location constraints.
Published: 02/03/2014
Published: 02/03/2014
An independent operator in the Eagle Ford focuses on the optimization of field development operations with the goal of finding the most effective and efficient methods to complete the wells to generate economic production rates and recoveries. The operator typically uses the plug-and-perf technique, with the following parameters per stimulation stage: an interval length of 200 ft and four perforation clusters.
The interval length dictates the required number of plug-setting operations along the wellbore, and therefore completion times, as well as operational costs. Extending the interval length without altering the spacing between perforation clusters would provide a solution to reduce time and cost. However, limitations on treating rate and fracture gradient anisotropy could lead to ineffective fracturing-fluid distribution among the increased number of clusters within the interval, potentially compromising well productivity and estimated ultimate recovery (EUR). An effective stimulation technique that would optimize fluid and proppant allocation was required.
BroadBand Sequence fracturing service was used in one well to evaluate the ability to address the challenge. For the candidate well, the interval length was tripled to 600 ft, greatly reducing the total number of bridge plugs required. The number of perforation clusters per interval was also tripled (to 12) by keeping the spacing between clusters unchanged. For a fair test, the amount of proppant per unit length of lateral and the pumping rate were also kept the same as for a conventional completion. Three stimulation stages were used per interval, separated by two pills of composite fluid.
Eight intervals were stimulated, separated by seven bridge plugs. The eighth interval was 400 ft long and therefore needed only two stages of proppant (separated by one pill of BroadBand service composite fluid), resulting in 23 stages. The total operating time for stimulation, milling out the plugs via CT, and subsequent cleanout was 56 h. An equivalent 23-stage operation using the conventional completion technique would have required 22 plugs and 104 h.
The effectiveness of the BroadBand Sequence service was confirmed through surface pressure responses and tracer logs. Based on 60 days of oil-, water-, and gas-rate measurements, production from the candidate well was on par with a comparable offset well completed conventionally. The BroadBand Sequence service provided 46% savings in completion time and 68% savings in plug costs, helping the operator achieve a higher rate of return.
Challenge: Improve operational efficiency and reduce well completion costs without compromising oil production and recovery in the Eagle Ford.
Solution: Apply the BroadBand Sequence fracturing service, which uses a composite fluid comprising a proprietary, fully degradable blend of particles and fibers to enable stimulation of longer intervals.
Results: Reduced total completion time by 46% and the number of plugs by 68% compared with conventional techniques, while maintaining well productivity.