Horizontal producers completed with multiple hydraulic fractures have proved cost effective in several North Sea low permeability chalk fields1,2,3,6,7 . This paper describes the evaluation of the optimal stimulation type and spacing for five South Arne pre-drilled producers that were planned to fill the process design capacity.
The initial design work consisted of both analytical and numerical simulation methods. These were calibrated using a South Arne porosity to permeability transform, stimulation design software predicted fracture geometries and offset field production experience.
Most wells were drilled in a direction that was parallel to the hydraulic fracture orientation. Propped fractures placed in a near tip to tip fashion were found to be the optimal design. Based on this and the initial production data a batch completion operation was performed and the platform capacity reached. A comparison with two years of production history has been made which supports the main initial design assumptions and results. Earlier papers on the stimulation and completion work of the South Arne development1,6,7 are complimented by the reservoir engineering issues covered in this paper.