Memo from Attorney Stuart Smith with Smith Stagg Law Firm
Note: The following memo was drafted after a thorough review of industry and professional message boards, articles and comments, the accounts of witnesses and discussions with various oil and gas professionals. It contains opinions of petroleum engineers who work in my office, as well as opinions and thoughts held by persons who have written and commented on the disaster as to what could have happened to the DEEPWATER HORIZON. BP and others have released very few facts so far and due to the dearth of information at the moment, there is no way to know what truly happened.
Due to this total lack of transparency by BP and Halliburton, a team on independent lawyers, on behalf of the United Commercial Fisherman’s Association and the Louisiana Environmental Action Network (LEAN), prepared subpoenas on May 4 from the U.S. District Court in and for the Eastern District of Louisiana to compel BP to provide pertinent information regarding the cause of the DEEPWATER HORIZON catastrophe and its potential impact on human health and the environment. These subpoenas can be downloaded at http://www.kreweoftruth.com
BP could clarify a lot of these issues by being transparent and releasing information to the public and to industry. Such information would be the cement bond logs, the driller’s reports, the identity of the company that performed the pressure testing (M-I or Halliburton), the full video from the ROV’s, pressure data, results of the well’s flow potential tests, whether or not they were running a tool at the time of the blowout, whether the mud in the marine riser had been displaced, and all the other data that was streamed to Houston from the rig, leading up to the explosion. This is information owed to the public, it should no longer be considered proprietary and kept secret for BP’s economic benefit.
I am going to provide an overview of what I think most likely happened at the rig. I will try to be as thorough as possible, but this is highly technical stuff and there are lots of unknowns at this point. Having been through all of this, I think that M-I, LLC will likely have to be included in the suit for negligent pressure testing and/or mud systems management.
I have been through this account, as well as countless articles and comments on the technical message boards and forums. The professionals seem to question this guy’s experience/position and suggest he may be misinformed/mistaken as to some of the technical stuff in the interview. However, he does corroborate the recollections of the two fishermen who witnessed the explosion in that the mud in the marine riser had been displaced with sea water. The mud company was M-I SWACO. It is possible that M-I was the one who performed the negative pressure tests (inflow tests possibly using M-I’s Well Commissioner Tool) on the casing and cement plug. It is assumed this test showed integrity of the cement bond and plug, as well as the integrity of the seal assembly. “Mark” says that the BOP’s were also tested (this seems unlikely if they were about to temporarily plug the hole and move the rig, as the BOP’s would be removed once the final plug was set, so they were likely just testing the seal assembly and possibly replacing seals). At this point the drilling fluid in the marine riser was displaced with sea water. These synthetics are very expensive and BP would want to recover all that they could for sale back to M-I.
It now seems likely that either the casing developed microfractures or the cement plug did not set properly [they can be difficult to properly set in deviated (non-vertical) well bores, see Halliburton doc HAL.9002.004.0485] and thus did not function properly, allowing gas to migrate into the wellbore and build up pressure while the annular preventer was closed in the process of displacing the drilling mud.
It is also likely that the test results were flawed or the inflow test did not replicate the real situation, thus lulling the operators into a false sense of security in thinking they had a functioning cement plug in a fully cased hole. This sense of security combined with it being uninteresting work (P&A) occurring late at night and at the very end of the trip when people are tired and rushing to get the rig moved offsite, is likely what led to:
(i) BP deciding to displace the drilling fluid in the marine riser without concern for pressure build-up;
(ii) fail to follow SOP for the displacement process and to observe the warning signs of the kick (including monitoring the returns and attaching the choke/kill lines); and
(iii) finally to open the annular preventer without bleeding off pressure.
When the annular preventer was opened the kick entered the riser encountering the less dense seawater. The reduction in pressure caused a rapid expansion of the gas. The gas traveled up the riser displacing the seawater and sending it shooting all over the well before escaping itself. The gas was then ignited by some source causing an explosion.
The Shear Rams on the BOP are supposed to engage when the BOP loses communication with the well or when triggered by the driller up at the well. The Shear Rams are a secondary safety system, the primary safety system being the mud system which provides the pressure to counteract the formation pressure. The Shear Rams cut anything in the wellbore and seal off the well. However the Shear Rams failed to engage on the Deepwater Horizon, though the workers claim to have triggered them. At this point several things could have occurred:
(i) portions of the cement plug could have escaped with the gas kick and damaged the shear rams;
(ii) the high volume of sand escaping with the kick could have corroded the shear ram preventing a seal, which would then continue to erode;
(iii) the shear rams could have closed on the Well Commission Tool (pressure testing tool) or the tool connector or possibly a drill string connector and were not designed to cut through the thick metal alloys [if they were running a tool at the time of displacing the mud in the marine riser, then this seems the most logical scenario]; or
(iv) the production casing was not fully set and the casing moved up into the BOP when the well kicked and the shear rams could not cut the pipeline quality casing;
(v) the BOP simply malfunctioned and failed to engage (unlikely since the controls were operational in opening the annular preventer to release the kick and the rams are tested every 14 days)
It is likely that the explosion caused the controls on the rig to malfunction and thus if the rig workers did not hit the control until after the kick (the kick would have traveled very quickly up the riser), then the BOP would not close. Also if a tool joint or something else prevented the shear rams from closing (scenario iii or iv), then the rig controls would not be able to execute another command (i.e. trigger any of the redundant systems) because they have to complete a command before they can start a new one. Without non-functioning BOP’s the well quickly became a blow out. The rig sank and oil and gas started flowing through the wellbore up through the wellhead, past the non-engaged rams and into the drill string and marine riser which is still connected to the BOP’s.
The oil is leaking out of the riser/drillstring in AT LEAST 3 places at a rate of AT LEAST 5,000 bbl/day (probably greater). The only thing restricting flow right now seems to be the partially engaged rams and the kinked marine riser containing the drill string. BP plans to pressure test the Lower Marine Riser Package (LMRP) in the next couple days to analyze the possibility of shearing off the riser and fitting a new BOP on top of the current damaged BOP. The risk with this is that the riser could be the only thing restricting flow right now, so once they cut it they might not be able to get the new BOP affixed.
BP also plans to place dome structures over the leaks to collect the oil. It is highly unlikely the pumps will be powerful enough to get the oil to the surface at a sufficient rate and so it will escape out the bottom, unless a sufficient seal is obtained. The problem with this is that securing these domes in 5,000′ of water with a soft seafloor is going to make getting a good seal difficult to impossible. Additionally in placing the structure over the riser, the riser could shift causing it to fail completely or create additional leaks. This would remove flow restriction and lead to an increased rate. Also the pipe required to transport the oil to the surface could easily fail.
BP is also going to attempt to plug the drill string to stop the flow of oil out of it, but physics tells us that the flow will just be redirected towards the breaks in the riser and the increased flow could make it worse.
Basically it is likely that the only way to kill the well will be by drilling a relief well, which must be drilled directionally in 5,000′ of water to a depth of 18,000′ in a dangerous environment. BP cannot risk another disaster, so the well will be drilled properly and will not be rushed. It will take 2-4 months to drill, likely closer to 4 months.
Interview opportunities with Stuart Smith with Smith Stag Law Firm will be facilitated by emailing firstname.lastname@example.org or calling (850) 528-7668 (NATIONAL PRESS) or Cheron Brylski (504) 897-6110 (LOUISIANA PRESS).