Effective Torque Management of Wytch Farm Extended-Reach Sidetrack Wells

摘要

Wytch Farm was at the forefront of extended-reach drillingrn(ERD) during the 1990's. This was achieved throughrnopportunity, innovation, technology and team work. Late lifernmanagement of the field has now required that cost-effectivernsidetrack wells be drilled to sweep the remaining oil in placernin the offshore part of the field.rnAs with many ERD developments, one specific challengernassociated with the original Wytch Farm wells was the abilityrnto control torque and drag within manageable levels. Whilerndrilling the original ERD wells, it was noticed, by chance, thatrnthe addition of particular loss circulation material (LCM) hadrna profound impact on torque and drag. The mechanism byrnwhich this was happening was not fully understood at therntime, but considered to be a combination of hole cleaningrnimprovements and mechanical friction reduction.rnIn an attempt to quantify and better understand the frictionrnreducing mechanism, a series of controlled field experimentsrnhave been undertaken.rnThis paper describes the basis for the field experiments,rnimplementation plan, analysis techniques and results. Resultsrncorrelate the amount of LCM addition with a markedrnreduction in friction factor. The effectiveness of LCM sweepsrnfor torque and drag reduction is also discussed. Understandingrnthe relationship between LCM addition and torque and dragrnreduction will offer cost savings during the drilling of morerndemanding ERD wells. Explanations of the torque and dragrnreduction mechanism are also discussed in the paper.