Successful Broadband Drillstring Technology Uptake: From Field Test to Extended Reach Offshore Campaign
Authors: Veeningen Daan M. , Palmer Jason , Steinicke Greg D. , Saenz Jesus 
Published: April 2012

Extended reach offshore wells in Trinidad and Tobago are characterized by holecleaning challenges, wellbore instability, and downhole vibrations that damagetools and reduce the rate of perforation. To improve the performance in amulti-well drilling campaign and to reduce operational risks, the operatorsuccessfully tested and implemented a wired pipe or broadband networkeddrillstring system for an offshore campaign.

High-resolution data from downhole measurement tools and along string annularpressure evaluation was provided in real-time by the broadband network systemfor approximately 95% of the 84,000ft drilled during the trial period. From thevery first well onwards, the campaign achieved a significant reduction innon-productive time due to more accurate interpretation of wellbore conditionswhile drilling and reduction of wellbore conditioning practices or eveninitiating early responses to unfavorable trends. Hole cleaning was improved bythe ability to recognize inadequate drilling practices, optimize sweep strategyand reduce tool failures through downhole diagnostics, and stick-slip vibrationmitigation.

This paper describes the successful integration of high-definition downholeoperations through project management, collaboration with third party toolpartners and practical, scalable solutions to solve operational and logisticalchallenges. Further, the paper describes the experiences gained during thesystem installation on two rigs, managing the inventory, the commissioning ofan in-country shorebase and the pioneering of local repair and maintenance forspecialized networked drilling tools to the successful integration into theoperator's workflow and process for a multi-year campaign.

Challenges in Drilling Extended Reach Wells

Today's wells are characterized by their increased reservoir contact, which isachieved by drilling longer step-out wells and completing multilateral, horizontal wellbores. These wells represent a step-change in complexity fordrilling operations, and present additional challenges in terms of cleaning ofthe hole, managing the significant torsion in the drillstring, and limiting anybuckling of the drillstring or casing due to the well's geometry and length. Additional challenges in today's environment include high rig rates and deeper, hotter reservoirs in increasing water depths.

The operator's offshore wells in Trinidad and Tobago are high-angle withextended reach stepout and have historically been characterized by wellboreinstability, hole cleaning difficulties, and multiple problematic faults. Forthis reason, a field test program was designed with the objective todemonstrate the benefits of the networked drillstring system in helpingmitigate these problems. See Figure 1 for the approximate location.

Specifically, the first well of a set of five wells, was planned with a 10,000ft step out, a local record. It was determined that high-resolutiondensity image logs were required in real-time to better manage the occurrenceof wellbore instability. Further, the project required high-frequencypressure-while-drilling data to manage hole cleaning and pack off prevention inan environment where lost circulation is frequently experienced.