10 February 2009
Does anyone have any experience with using Baker NOV double acting
Hydraulic/Mechanical drilling jars.
We are currently using Smith Jars, and are looking at Baker/NOV.
Would be interested in any experiences with these good, or bad.
rp-squared Performance Co-ordinator
Well Ops Mgr
I sent some comments on our experience with the BOT/NOV jars to
Chris Fraser yesterday, but I will repeat them here for your benefit.
We used the Griffith double acting hydro mechanical jars on our
Tangguh development for about one year. We ran both 6 1/2" and 8"
jars but we found they did not perform very well, particularly when
we had hard jarring operations in the 12 1/4" hole. The main problem
was the mechanical latch wears quickly so the mechanical jar action
would eventually fail. We also had many occassions when the jars
would trip whilst POH making them more of a problem to handle at
surface. We tried a higher latch setting but this never really fixed
teh wear problem. We eventually decided to switch to the NOV
powerstroke hydraulic jar which we have found more reliable and
gives a good jar action. If you have no supplier choice I would
recommend the Powerstroke jar over the Griffith jar.
Well Team Leader
bp Tangguh, Indonesia