CASE STUDY
Hydra-Jar AP Drilling Jar and Accelerator AP Impact Tool Free Stuck BHA in 15 Minutes Runner jar placement software optimizes jar and accelerator position within wellbore to free BHA and resume normal drilling operations CHALLENGE Recover a 61 ⁄ 8-in directional BHA that could not be jarred free at 12,190 ft in a horizontal well section. SOLUTION Use a 4.75-in Hydra-Jar AP* doubleacting hydraulic drilling jar with a 4.75-in Accelerator AP* impact tool for increased effectiveness, aided by Runner* drillstring analysis program. RESULT Freed the stuck BHA after only 15 min of jarring down, significantly minimizing NPT and the associated costs.
Gain control of lost circulation zone While trying to gain control of a lost circulation zone in the lateral section of a horizontal well in Ward County, Texas, Texas, US, the directional BHA became stuck. After 7 hours of working, the 6 1 ⁄ 8-in pipe remained stuck at 12,190 ft, and the operator believed lost circulation material had caused the BHA BHA to stick stick..
Free drillstring components Schlumberger recommended using the Hydra-Jar AP double-acting hydraulic drilling jar in conjunction with the Accelerator AP impact tool for jarring up and down with hydraulic fluid for maximum impact, while protecting the drillstring and surface equipment from damaging shock waves. To ensure optimal placement of the jar and accelerator in the wellbore, an analysis was conducted using the Runner drillstring analysis program. The drillstring was was backed off at 60° and approximately 11,000 ft. The fish was more than 1,100 ft long. The fishing assembly was tripped in hole to engage the fish, and 25 bbl of PIPE-LAX † stuck-pipe additive, from M-I SWACO, a Schlumberger company, was pumped. Then jarring operations commenced.
Resume normal drilling operations After only 15 min of down jarring, the stuck BHA was freed and pulled out of the borehole, preventing protracted NPT and allowing the operator to quickly resume normal drilling operations. 450,000
9,000
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f b l , 300,000 t n i o p k 250,000 c u t s t 200,000 a t c a p 150,000 m I
6,000 Impact
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s / f b l , t n i o p k c u t s t a e s l u p m I
0 100,000
Surface overpull, lbf Output from the Runner program was used to model the optimal overpull weight to achieve the maximum jar impact force at the stuck point.
*Mark of Schlumberger † Mark of M-I L.L.C. Other company, product, and service names are the properties of their respective owners. Copyright © 2013 Schlumberger. All rights reserved. 12-DT-0211
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