News Article | April 17, 2017
An oil and gas production well operated by BP Exploration Alaska Inc. in Prudhoe Bay has stopped leaking oil but continues leaking natural gas, the Alaska Department of Environmental Conservation said in an Apr. 16 statement.
News Article | April 18, 2017
An oil and gas production well operated by BP Exploration Alaska Inc. in Prudhoe Bay has been killed and is no longer leaking natural gas, the Alaska Department of Environmental Conservation said in an Apr. 17 statement. Crews are now working to install a mechanical plug to permanently secure the well.
News Article | April 18, 2017
This April 2017 photo provided by the U.S. Environmental Protection Agency shows an oil well that was misting natural gas on Alaska's frozen North Slope. Workers from the Alaska Department of Conservation and the Environmental Protection Agency on Saturday, April 15, 2017, were able to connect hoses to valves that allow pressure in the well to be reduced, according to a statement from the state conservation department. The Environmental Protection Agency says a crack in the BP wellhead near Deadhorse sent up mist of crude oil Friday before it froze over and an initial leak stopped. (U.S. Environmental Protection Agency via AP) ANCHORAGE, Alaska (AP) — The Latest on a natural gas leak at a well on Alaska's North Slope (all times local): A leak of natural gas from an Alaska North Slope oil well was plugged by pumping salt water down the well. The Alaska Department of Environmental Conservation says the leak was plugged just after 3:30 a.m. Monday when the salt water offset upward pressure. The department says the well will not be officially secured until a mechanical plug is put in place. The well is operated by BP Exploration Alaska Inc., a subsidiary of BP. The gas leak accompanied by a spray of crude oil was discovered Friday morning. Responders say the crude oil spill appears to be limited to the drilling pad. Responders will try to confirm that crude oil did not reach nearby tundra. Officials say a leak of natural gas at an oil well on Alaska's North Slope has been plugged. Alaska Department of Environmental Conservation spokeswoman Candice Bressler says the well operated by BP Exploration Alaska Inc., a subsidiary of BP, was successfully controlled overnight. BP employees discovered an uncontrolled natural gas leak Friday at a well five miles from the Deadhorse airport. Within an hour, they detected that the well also was spraying a mist of crude oil. BP set up a unified command with state and federal regulators to address the leaking gas and oil. By Sunday responders had managed to close a valve that stopped the spray of oil. Officials say oil likely spilled only on the well pad and not nearby tundra. Oil field workers have reduced the pressure in an oil well that is leaking natural gas on Alaska's frozen North Slope. The Alaska Department of Environmental Conservation says workers Saturday night were able to connect hoses to valves that allow pressure in the well to be reduced. Pressure in the well was monitored all night and excess pressure released from the well. Leaks were first detected Friday in the well operated by BP Exploration Alaska Inc., a subsidiary of BP. A crack in the BP wellhead near Deadhorse sent up spray of crude oil Friday. Closure of a safety valve stopped the spray of crude oil. An unknown about of oil reached the well pad. Responders say they don't believe it reached tundra off the pad but they can't confirm that until the well is plugged and it's safe for most workers to return to the drilling pad. A previous version of the story incorrectly stated the name of the Alaska Department of Environmental Conservation. The story also incorrectly said state and federal workers rather than oilfield workers had reduced pressure in the oil well.
News Article | April 18, 2017
This April 2017 photo provided by the U.S. Environmental Protection Agency shows an oil well that was misting natural gas on Alaska's frozen North Slope. Workers from the Alaska Department of Conservation and the Environmental Protection Agency on Saturday, April 15, 2017, were able to connect hoses to valves that allow pressure in the well to be reduced, according to a statement from the state conservation department. The Environmental Protection Agency says a crack in the BP wellhead near Deadhorse sent up mist of crude oil Friday before it froze over and an initial leak stopped. (U.S. Environmental Protection Agency via AP) ANCHORAGE, Alaska (AP) — An oil well leaking natural gas on Alaska's North Slope was successfully plugged by pumping saltwater into the well, according to private and government responders. The state Department on Environmental Conservation on Monday said the well operated by BP Exploration Alaska Inc., a subsidiary of BP, was "killed" at 3:35 a.m. The well is five miles from the airport at Deadhorse. Employees on Friday morning discovered uncontrolled natural gas flowing from the top of a well house, a metal structure that looks like a large box over a well. About 45 minutes later, they determined that the well was spraying a mist of crude oil into the air. BP reported the leak and set up a joint response team with state, federal and municipal responders. A weekend statement from the "unified command" said two leaks were detected. Oil was spraying from a leak near the top of the well. Workers contained that leak by activating a safety valve. Oil droplets likely were contained to 1.5 acres (0.61 hectares) of the drill pad, responders said. They were waiting for the well to be plugged to determine if oil reached nearby snow-covered tundra. Responders determined the well had risen up to 4 feet (1.22 meters) causing a pressure gauge to break off and preventing responders from pumping material into the well to kill it. Responders on Saturday night were able to enter the well house and connect hoses to valves. That allowed the bleeding off of gas from space around the well's below-ground piping and a reduction in gas pressure. Responders from Boot and Coots Services, a well-control contractor, entered the well house and placed a plug in the above-ground piping. That allowed responders to pump in a solution of methanol and saltwater, killing the well. The temperature at the site Monday was 21 degrees F (-6.11 Celsius). The nearest village, Nuiqsut (noo-IK-sit), is 50 miles (80.46 kilometers) away. An earlier version of this story listed an incorrect name for the Alaska Department of Environmental Conservation. The story also incorrectly said federal and state workers, not oil field workers, reduced pressure in the oil well.
Ferre E.C.,Southern Illinois University Carbondale |
Michelsen K.J.,University of New Mexico |
Ernst W.G.,Stanford University |
Boyd J.D.,BP Exploration Alaska Inc. |
American Mineralogist | Year: 2012
Petrological and geochemical variations within plutons reflect their magmatic and emplacement histories. Here we present new magnetic susceptibility (Km) data on the ∼163 Ma Barcroft granodiorite pluton in eastern California, which is exceptionally well exposed, especially in the vertical dimension. The Barcroft pluton offers exposures over a total of 2560 m of elevation and is an appropriate target to investigate variations of magnetic susceptibility. In ferromagnetic plutonic rocks, Km reflects mainly the abundance of magnetite, whereas in paramagnetic plutonic rocks it reflects primarily the abundance of mafic silicates. Magnetic susceptibility is also determined by magmatic processes such as crystal fractionation and by intensive parameters such as oxygen fugacity. Other magmatic processes, including magma replenishment, hybridization, and host-rock assimilation, may also influence Km variations. A first data set is based on 622 core samples that were measured in the laboratory. Our second data set comes from 1960 field measurements collected at 196 stations between ∼1600 and 4000 m elevation. Detailed surveys were performed at the outcrop scale to evaluate the impact of the ∼100 Ma McAfee Creek intrusion on the Barcroft background magnetic susceptibility. The combined data sets display a broad positive correlation between Km and elevation. Pluton mineralogy also appears to vary with elevation but is more difficult to quantify. At the outcrop scale, small dikes of the McAfee Creek granite transect the pluton and are responsible for a decrease in Km of the host granodioritic rocks toward the dikes due to late-stage magmatic or hydrothermal alteration. A contour map of K m shows a high degree of correlation with local topographic features such as deep canyons. Magnetic susceptibility of the Barcroft mafic rocks varies at the outcrop scale as a result of presence of petrological heterogeneities. However, these small-scale variations are embedded in a broader magnetic susceptibility trend due primarily to elevation, which reflects petrologic stratification of the pluton. The late-magmatic and hydrothermal alterations described in previous studies do not affect the spatial distribution of magnetic susceptibility. We propose that vertical increase of Km was primarily caused by crystal fractionation or another magmatic differentiation mechanism rather than by an externally driven increase in oxygen fugacity toward the roof of the intrusion.
Svedeman S.J.,Southwest Research Institute |
Brady J.L.,BP Exploration Alaska Inc.
Proceedings - SPE Annual Technical Conference and Exhibition | Year: 2013
Laboratory tests were conducted to evaluate the effectiveness of oil/water separation in a deviated well casing that is located below the perforation intervals. Downhole water separation and reinjection is needed to reduce well operating costs associated with producing large amounts of water to the surface. In the casing separator, produced water flows downward from the well perforations with entrained oil buoyantly separated to the topside of the casing. A dip tube, running to the bottom of the casing, feeds a downhole pump that pumps the water into another level in the reservoir. A test facility was constructed to test the casing separator performance at a variety of well inclination angles, production flow rates, water cuts, and reinjection water flow rates. At each operating condition, the amount of oil entrained in the reinjection water was measured to determine the maximum amount of water that could be separated and still provide "clean" water to the downhole pump. Tests were conducted over well inclination angles from 18° to 75°. The maximum water velocity in the casing separator, for clean water, varied from 0.2 ft/sec to 0.4 ft/sec. The test results provided the information needed to determine how much water could be separated in the casing separator. With the separator performance data, the economics of reinjecting water with a downhole pump could be evaluated. Copyright 2013, Society of Petroleum Engineers.
Hunter R.B.,C and A Energy Services |
Collett T.S.,U.S. Geological Survey |
Boswell R.,U.S. National Energy Technology Laboratory |
Anderson B.J.,U.S. National Energy Technology Laboratory |
And 5 more authors.
Marine and Petroleum Geology | Year: 2011
The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The "Mount Elbert" site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate scientific research programs can be safely, effectively, and efficiently conducted within ANS infrastructure. The program success resulted in a technical team recommendation to project management to drill and complete a long-term production test within the area of existing ANS infrastructure. If approved by stakeholders, this long-term test would build on prior arctic research efforts to better constrain the potential gas rates and volumes that could be produced from gas hydrate-bearing sand reservoirs. © 2010 Elsevier Ltd.
Sacks A.,Pennsylvania State University |
Sacks A.,BP Exploration Alaska Inc. |
Saffer D.M.,Pennsylvania State University |
Saffer D.M.,BP Exploration Alaska Inc. |
Fisher D.,Pennsylvania State University
Geochemistry, Geophysics, Geosystems | Year: 2013
We use a high-resolution 3-D seismic survey to map a population of recent normal faults within the Kumano Basin of the Nankai subduction zone, in order to quantify patterns of strain and stress state over the last 0.44 Myr. We identify distinct fault populations that define three phases of extension. Phases 1 and 2 comprise NW-SE striking faults located along the western basin edge and in the northwestern portion of the study area, respectively. The NE-SW striking faults of phase 3 comprise the largest population, and extend ~20 km landward from the basin's seaward edge. Phase 2 faults typically terminate within a few reflectors of the seafloor, whereas most phase 3 faults form seafloor scarps. Inversion of the fault populations documents NE-SW extension during phases 1 and 2 and NW-SE extension during phase 3, consistent with both core-scale structures and horizontal stress orientations observed at Integrated Ocean Drilling Program (IODP) boreholes. Slip on phase 3 faults accommodates strain of up to ~1-2%, concentrated near the basin's seaward edge. Inversion for a best-fit stress tensor yields a subvertical σ1 and subhorizontal σ2 and σ3 for all faulting phases. We find that during phase 3 in most portions of the basin, σ2 = σ3 (SHmax = Shmin), reflecting widely varying fault strikes. This contrasts with distinct S Hmax and Shmin magnitudes inferred from IODP borehole data; these observations may be reconciled if the orientation of maximum horizontal stress fluctuates due to variation of subduction parallel compression through the seismic cycle. ©2013. American Geophysical Union. All Rights Reserved.
La Plante W.C.,BP Exploration Alaska Inc.
Welding Journal | Year: 2012
Experts state that knowledge of welding technology, engineering, and inspection are crucial to the Prudhoe Bay oilfield operations at the North Slope and the Trans-Alaska Pipeline System (TAPS) infrastructure. Accurate work-force manning estimates are required for pipeline applications, such as pipe replacement and repair, pipeline construction replacement and repair, and pipeline construction. Special training is provided for personnel traveling to Prudhoe Bay for the first time that covers safety and health criteria, environmental regulations, policies, and procedures; and workplace hazard awareness. Specific consideration is given to the acquisition of critical personnel in addition to project material and equipment requirements. Mechanical testing and fracture toughness of weld metal and base materials also represents a critical characteristic in Performance Qualification Record (PQR) and welder performance qualification.
Wilkes J.C.,Southwest Research Institute |
Wade J.,Southwest Research Institute |
Rimpel A.,Southwest Research Institute |
Moore J.,Southwest Research Institute |
And 3 more authors.
Proceedings of the ASME Turbo Expo | Year: 2016
High speed foil bearings are currently used in increasingly demanding, high performance applications. The application under consideration is a 120 krpm natural gas turboexpandercompressor, which requires 38 mm (1.5 in.) foil journal bearings with high stiffness and load capacity to help enhance rotordynamic stability. This paper describes the development of the foil bearing for this application and includes measured stiffness and damping coefficients recorded on a high-speed dynamic bearing test rig. The dynamic test data were taken for several different foil bearing configurations with varying spring-element foil thicknesses, number of spring-element foils, and bearing shim thickness. All three parameters have a direct impact on bearing clearance. The influence of these different parameters on measured stiffness and damping coefficients and thermal performance of the bearings are presented and discussed. Copyright © 2016 by ASME.