Before you say to yourself, oh, this will all be fine, consider the complexity of achieving success with relief wells. As this author has already noted, it can take many weeks to mill through the original well casing once the relief well intersects it at around 18k feet. And that itself is hardly guaranteed, these wells are hard to drill, and frequently fail.
This guy considers, if the first relief well succeeds, a target date of around September to be realistic, and August to be too best case to be considered as a real goal. And that’s IF and ONLY IF the first well A: intersects the existing well, and B: doesn’t fail in the process.
In the Ixtac blowout, it took 10 months and numerous relief well attempts before they succeeded.
Here we have another oildrummer drilling guy, aliilaal, explaining a bit about why Relief Wells (RW) are so complicated. Keep in mind that the relief wells are what will actually fix the problem, everything else is just a stop-gap measure.
aliilaali on June 1, 2010 – 12:36am Permalink | Subthread | Comments top
idle thoughts on problems in hitting the target with RW ….had said my 2 cents on wellbore surveys and now form the RW standpoint there are some things to consider with regards to RW target
1- like i’d said ….current technology’s theoretical limits can hit a 10ft radius ball with a confidence interval of 90%…this limit applies on RW with with a grain of salt since expected interception is 18000 rkb ….but really depth can be +- 50 ft on depth …the problem here is azimuth of RW (think 3d geographical grid) ….so essentially the target for the RW is not a circle but a rectangle (in cross sectional view of leaking well when looked at from right or left) of approx 75′ (length) x 2′ (width)
2- now there are two options to establish pressure communication b/w RW and LW (leaking well)…(1) mill into the LK csg or run a hot tap (pull along LK and run a perf gun)….high pressures will likely preclude a hot tap and most likely it will be the milling option