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Content: David Izon Pagemasters:
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Gulf of Mexico Region Losses of Well Control - 2003 (5 total) March 8, 2003 – Anadarko E&P Company
Remarks: The objective of the workover was to replace parted tubing and return the well to production of gas from the “P” sand. The “P” sand had been pressure depleted to a gradient of approximately 2.7 pounds per gallon (ppg) by seven years of production. Because of the under-balanced, depleted pressure of the formation, and the need to retain productivity with minimum formation damage, the workover employed light-weight fluid. Workover fluid loses were to be controlled by spotting gel lost circulation material (LCM) pills. During the workover of the Well, after the tree had been removed and the blowout preventer (BOP’s) installed, preparations to begin recovering the tubing down to a suspected break or part at about 1,900 ft were initiated. High pressure was then unexpectedly observed to be abruptly rising on the tubing and production casing annulus. When the pressure reached approximately 6,150 pounds per square inch (psi), the tubing hanger and approximately 600 feet of tubing were suddenly ejected from the well through the BOP’s. Subsequently, the well flowed out of control through the BOP stack. Attempts to control the well with the BOP’s were unsuccessful because of the tubing lodged across the BOP stack. The BOP stack was not equipped with shear rams. The Rig was subsequently evacuated and the Well then flowed uncontrolled for between one and four hours, when flow ceased and the Well bridged over. Normal well-control operations were then commenced and the Well was subsequently controlled, the perforations isolated, and the Well recompleted to a shallower sand. No injuries were sustained by the crew and no significant damage was sustained by the Rig. From calculations by the Operator, only a portion of the “O” Sand would have been open to sustained flow after the initial casing blowdown. Therefore, the Operator estimates approximately 1 MMcf and 10 barrels of condensate were blown out of the Well with the uncontrolled gas flow, most of which is assumed to have spilled into the ocean. According to testimony, as a result of the spill, a light, broken, streaky sheen measuring approximately 2 miles by ½ mile was visible the next morning. Following the incident, the Fast Response Unit (FRU) motor vessel Bastin Bay from Clean Gulf Associates was mobilized and arrived approximately 10 hours after the loss of control. No recoverable oil was on the water and the sheen fully dispersed or evaporated by noon. Pollution control operations by the FRU were not deemed feasible and were not commenced. However, the Bastin Bay remained on site for approximately one week on stand-by in case additional problems developed during well-control operations. See OCS Report MMS 2004-048 for more details. April 12, 2003 – Helis Oil & Gas Corporation
Remarks: The lead operator recorded the tubing pressure from a gauge located in the tree cap of Well A-2. After obtaining the tubing pressure, the lead operator left the platform without removing the pressure gauge or installing a plug in the needle valve. The lead operator also left the crown valve open. The o-ring in the tree cap failed while the platform was unattended, allowing gas and condensate to be vented into the atmosphere. While conducting a morning check, an operator observed the well blowing natural gas out of the well cap. Personnel from a nearby platform were sent by boat to the facility, and they activated the boat dock ESD. The well stopped flowing approximately 30 seconds after the ESD was activated. The master, wing and crown valves were then closed. An investigation revealed that Well A-2 was blowing out at the hammer type cap located on top of the wellhead. The gas was coming from a bleed-off hole (weep hole) on the hammer type cap. The cap gasket was pinched, allowing gas to flow. Approximately one gallon of condensate was spilled into the Gulf. April 22, 2003 – ChevronTexaco Corporation
Remarks: The CA-3 well had been permitted with the requirement of a conductor casing string waived because (1) four previous wells drilled from the platform had encountered only routine sand-shale sequences to the depths projected for surface casing, (2) a log of the CA-7 surface hole had shown no resistivity, and (3) the original shallow hazard seismic survey indicated no shallow zones potentially productive of hydrocarbons. However, once the CA-3 drive pipe was drilled out, an anomalous, thick sand deposit was immediately encountered that initially caused large seepage losses and finally complete loss of drilling fluid returns. The drilling plan was subsequently modified and a string of conductor casing was run to 913 ft and cemented. Because no cement returns were received at the surface, a top cement job was performed. When the conductor casing was subsequently drilled out, the anomalous sand deposit continued to be encountered to a depth of 4,800 ft where surface casing was to be set, with significant seepage losses continuing. At 4,800 ft, a short trip was made to prepare to set surface casing. During tripping, returns were totally lost with the bit at 3,985 ft. After the bit was pulled back into the shoe, the hole ceased taking fluid and then began flowing. The annular was closed and the diverter lines opened, and after a slight belch of gas, the diverter flowed water. The flow from the well fluctuated in cycles for eight hours, alternately flowing/unloading and then taking fluid. After eight hours, flow ceased and the well began taking fluid. Normal lost circulation operations were initiated and surface casing was finally run to 3,883 ft, apparently sealing off the thief zone and zone of influx. No indication of solids was found in the diverted stream and only minimal gas; no sheen and no pollution were observed. See OCS MMS 2004-048 for more details. September 2, 2003 – Manti Operating Company
Remarks: The M/V Fugro Explorer was positioned near the Parker 14-J jack-up rig in 38 feet of water. The Fugro Explorer was coring at 1030 hours and drilled through a gas pocket. Gas started venting to the surface of the water. There was no pollution, and the Fugro Explorer winched itself off location. At 1115 hours all non-essential personnel were evacuated from the Parker 14-J. At 1130 all personnel were evacuated. At 1140 hours, the gas stopped venting to the surface. At 1200 all personnel were returned to the rig. Divers inspected the sea floor around the rig and found no erosion. December 4, 2003 – Walter Oil & Gas Corporation
Remarks: A lift boat, which was mobilized in order to set the production deck, arrived at the location and set up approximately 50 feet from the caisson. After the preload period, the Nav-Aid and upper ladder section of the caisson were removed. The construction crew was prepping the tree for the removal of the top four valves on the tree to facilitate the stab-over of the production deck. Three construction personnel were hoisted in a workbasket to the tree. The personnel were equipped with portable gas H2S detectors and a fire extinguisher. The pressure gauge at the top of the tree was checked and showed zero pressure. The personnel then checked the needle valves at the base of the tree for pressure. The first needle valve was checked and found to have minimal pressure that bled off almost instantly. This needle valve accessed the control line of the SCSSV. The second needle valve, which accessed the downhole chemical injection line, had a check valve installed at the end. When the construction personnel attempted to back out the check valve, the autoclave needle valve came off the seat. This resulted in gas from the wellbore being released into the atmosphere. The crane operator immediately lowered the men in the workbasket down to the boat landing level to get them away from the gas release. The personnel were transferred back to the deck as they indicated they were all right (i.e., no indications of dizziness, burning eyes, nausea, trouble breathing, etc.). The probable causes of the incident were the following: 1) the failure of the construction operator to properly remove the plug from the autoclave valve, 2) a lack of company supervision during the operation, and 3) a failure of the operator to implement the H2S contingency plan. Damage is estimated at $400. Privacy | Disclaimers | Accessibility | Topic Index | FOIA Last Updated: 06/24/08, 02:48 PM
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