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Technical Paper: Application Of Tandem Rotary Steerable-Positive Displacement Motor Bottom Hole Assembly In Drilling Horizontal Wells: Case Study Of Three Eastern Siberia Wells

Society: IADC
Paper Number: 140241
Presentation Date: 2011
 Download: Application Of Tandem Rotary Steerable-Positive Displacement Motor Bottom Hole Assembly In Drilling Horizontal Wells: Case Study Of Three Eastern Siberia Wells (5.94 MB PDF) Login | Register

 

Abstract

The Vankor field in East Siberia is predominantly developed using horizontal wells drilled into the Yakolev and Nizhnekhet reservoirs. The field consists of pad clusters resulting in complex well trajectories. The field location is remote with complex logistics; therefore any directional drilling technology deployed must be robust and reliable. Traditionally, the wells have been drilled with steerable PDMs, in 2008 RSS tools where introduced along with LWD technology and this provided significant performance improvements in the 8-5/8" and 6" sections.

To further improve on drilling performance an engineering study was conducted in 2009 to assess further opportunities for increasing the annual cumulative meters drilled on the project. Several areas of opportunity were identified, a key recommendation of the study is the introduction of "Tandem Rotary Steerable-Positive Displacement Motor" BHA’s in the 8-5/8in section.

These new BHA designs deliver better drilling performance in terms of directional control and penetration rates outperforming conventional power drilling with over 350% improvement in ROP and 12 days saved per well section. Some limitations of the system include inability to deliver consistent DLS in excess of 4 deg/30m and rig hydraulics capacity constraints. The drilling cost savings realized from applying this new technique is in excess of $500,000 per well.

This paper discusses the results from the three wells drilled using the Tandem RSS-PDM BHA solution including aspects of the BHA design, drilling dynamics modeling and key performance indicators. The paper proposes new technology solution to the DLS limitations; a new generation hybrid rotary steerable tools that can deliver up to 15 deg/30m. They can be incorporated in Tandem RSS-PDM BHA designs. These new system have wider application and will allow another step change in horizontal drilling performance.

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