The Use of Wired Drillpipe Technology in a Complex Drilling Environment Increased Drilling Efficiency and Reduced Well Times

Abstract

This paper presents and discusses the results of a case study where Wired Drillpipe (WDP) technology was implemented on the Martin Linge offshore field development project in the Norwegian sector of the North Sea. Martin Linge’s resources consist of a shallow oil reservoir and several, deeper, structurally complex, high pressure gas and condensate reservoirs. The oil reservoirs are being developed with long horizontal wells and several deviated wells are drilled to unlock the gas and condensate reserves. The field was initially discovered in 1975 but proved too complex to develop at the time. Over the years several exploration and appraisal wells were drilled within a narrow pressure window, with multiple BHA runs per section. The complex drilling environment posed many challenges including severe losses, influxes, unstable formations and excessive downhole shock and vibrations resulting in poor MWD/LWD signal. WDP telemetry enables bi-directional, high speed data transmission to and from downhole tools at speeds up to 57,600 bps (Olberg et al. 2008). Conventional telemetry methods only provide very limited bandwidth (8-12 bps) for real-time data transmission and can suffer from signal reliability under adverse conditions, for example: no mud pulse data transmission to surface when pumps off or at flowrates below tool settings, decoding issues during high levels of downhole shock and vibrations and unfavorable mud conditions, such as gelled cold mud, gas, high viscosity pills, mud additives etc. WDP technology was implemented on the Martin Linge field development from the start of the development. The technology introduction cost off-set against the quantifiable benefits for the project was initially calculated close to break-even. Furthermore, the high upside potential associated with the use of this technology should allow improved well placement and have a positive effect on the quality of the drains drilled. This paper will summarize how the high speed telemetry provided by WDP enables wells to be drilled without the typical limitations imposed by conventional telemetry methods. The analysis will focus on two areas of efficiency and performance improvement. Firstly, the quantified data transmission time savings due to the real time high speed transfer of critical data between downhole and surface will be discussed in detail. Secondly, the network performance, drilling performance, application of new technology and technology investment cost will be discussed.