Telemetry Approach Enables Optimal Well Placement Despite Geohazards

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 219627, “Use of Along-String Measurements and High-Speed Telemetry for Geohazard Mitigation and Improved Risk Management Delivers Enhanced Operational Efficiency and Enables Optimal Well Placement in Challenging Offshore and Onshore Applications, ” by Stephen Pink, SPE, NOV, and Dale Bradley and Johnathan Rice, DCOR, et al. The paper has not been peer reviewed. _ Wired drillpipe (WDP; high-speed telemetry), along-string measurements (ASMs), and advanced logging-while-drilling (LWD) tools have been deployed in multiple wells worldwide to address specific challenges that typically have been either insurmountable with other techniques or likely to experience suboptimal results with alternative technologies. The complete paper discusses use cases in which high-fidelity pressure and dynamics measurements, combined with high-speed telemetry, were used to address complex geotechnical challenges such as low overburden, shale reactivity, and karstified reservoirs. Introduction Across global operations with multiple operators, several modern and very simple rigs have been equipped with surface interfaces and a high-speed wired network. Key components in the system include the wired bottomhole assembly, including LWD and an interface sub. This allows streaming of formation evaluation data at approximately memory quality, depending on tool firmware. The wired network itself is made up of wired double-shouldered tubulars and wired tools such as jars, network boosters for managing the downhole network, and distributed measurements in the form of ASMs, which enable the acquisition of dynamics and pressure data along the drillstring independent of flow. In addition, a high-resolution drilling-mechanics tool can be run to obtain downhole weight on bit and downhole torque. At the surface, a swivel assembly pulls data from the network while rotating and a device mounted on the bales enables the acquisition of all downhole data while tripping on elevators. This device is referred to as “data while tripping. ” The data is decoded at the network controller, distributed to either the technology provider or service company, and shared with the operator’s drilling and subsurface teams. Now that this data is available at surface, it must be converted into actionable intelligence for well placement or for improved understanding of wellbore conditions and system dynamics. Much of the complete paper discusses how this technology, partnered with others, was an enabler for the successful completion of uniquely challenging wells. The complete paper includes four case studies, with two included in this synopsis. The case studies not included in this synopsis involve offshore California (ultralow-overburden, geologically complex extended-reach-drilling wells) and offshore Norway (need to manage shale reactivity).