Halliburton in spotlight in gulf spill probe 
 
 Investigators look at the company’s role in cementing the deepwater drill hole in the Gulf of Mexico. Transocean and BP also face questioning. 
 
 In a statement Friday, Halliburton said: "It is premature and irresponsible to speculate on any specific causal issues.… The cement slurry design was consistent with that utilized in other similar applications… [and] tests demonstrating the integrity of the production casing string were completed." 
 
 Halliburton Chief Executive David Lesar is scheduled to testify before Waxman's energy and commerce committee on May 12, along with top executives Lamar McKay of BP America Inc. and Steve Newman of Transocean Ltd., which leased the drilling rig to BP. 
 
 Two members of Congress, Reps. Henry A. Waxman (D-Beverly Hills) and Bart Stupak (D-Mich.), called on Halliburton on Friday to provide all documents relating to "the possibility or risk of an explosion or blowout at the Deepwater Horizon rig and the status, adequacy, quality, monitoring, and inspection of the cementing work" by May 7. 
 
 Investigators delving into the causes of the massive gulf oil spill are examining the role of Houston-based Halliburton Co., the giant energy services company that was responsible for cementing the deepwater drill hole, as well as the possible failure of equipment leased to British Petroleum. 
 
 After an exploration well is drilled, cement slurry is pumped through a steel pipe or casing and out through a check valve at the bottom of the casing. It then travels up the outside of the pipe, sheathing the part of the pipe surrounded by the oil and gas zone. When the cement hardens, it is supposed to prevent oil or gas from leaking into adjacent zones along the pipe. 
 
 As the cement sets, the check valve at the end of the casing prevents any material from flowing back up the pipe. The zone is thus isolated until the company is ready to start production. 
 
 The process is tricky. A 2007 study by the U.S. Minerals Management Service found that cementing was the single most-important factor in 18 of 39 well blowouts in the Gulf of Mexico over a 14-year period. 
 
 Halliburton has been accused of performing a poor cement job in the case of a major blowout in the Timor Sea off Australia last August. An investigation is underway. 
 
 In its statement, the company said: "Halliburton originated oilfield cementing and leads the world in effective, efficient delivery of zonal isolation and engineering for the life of the well, conducting thousands of successful well-cementing jobs each year." 
 
 The company had four employees stationed on the rig at the time of the gulf accident, all of whom were rescued by the Coast Guard. It had completed the final cementing of the well and pipe 20 hours before the blowout April 20. 
 
 But at the time of the accident, "well operations had not yet reached the point requiring the placement of the final cement plug, which would enable the planned temporary abandonment of the well," the Halliburton statement said. 
 
 Experts were cautious about attributing blame, pending what are expected to be lengthy investigations by Congress and the Department of Homeland Security, which oversees the Coast Guard. 
 
 "What we do know is that highly pressurized oil is coming out of the wellhead with no control possible at this time," said Richard Charter, a drilling expert with the Defenders of Wildlife. "For that to happen, at least three redundant fail-safe mechanisms on and below the rig had to either fail to operate or not have been properly installed." 
 
 Charter said a piece of equipment known as the blowout preventer is required to shut automatically, according to regulations by the Minerals Management Service. "And it obviously did not," he said. ||||| AP Photo/Ron Edmonds 
 
 The Gulf of Mexico oil spill could end up being the worst American man-made environmental catastrophe of this generation. With the oil still spilling and investigations into the causes yet to come, it's too early to neatly assign blame to any one person. But for now, let's hold Dick Cheney personally responsible for the whole thing. 
 
 Here's the evidence: The Wall Street Journal reports that the oil well didn't have a remote-control shut-off switch. The reason it didn't have a thing that it seems every single offshore drilling rig should have? According to environmental lawyer Mike Papantonio, it's because Dick Cheney's energy task force decided that the $500,000 switches were too expensive, and they didn't want to make BP buy any. 
 
 Is that not enough reason to blame the former Dark Lord of the Naval Observatory? Guess what: Halliburton is involved, too! The Los Angeles Times reports that BP contracted Dick Cheney's old company to cement the deepwater drill hole. Cementing the hole was, according to the U.S. Minerals Management Service, "the single most-important factor in 18 of 39 well blowouts in the Gulf of Mexico over a 14-year period." And Hallburton is already under investigation for faulty cementing in an Australian well last year. 
 
 The spill will very likely destroy the fragile economies of at least five states and it could even plunge the nation back into a recession. So thanks, Dick. Nice work. ||||| (See Corrections & Amplifications item below.) 
 
 Associated Press A worker looks over an oil boom as it collects oil from the leaking Deepwater Horizon pipeline in the Gulf of Mexico. The disaster has been sending 1,000 barrels of oil a day gushing into the sea. 
 
 The oil well spewing crude into the Gulf of Mexico didn't have a remote-control shut-off switch used in two other major oil-producing nations as last-resort protection against underwater spills. 
 
 The lack of the device, called an acoustic switch, could amplify concerns over the environmental impact of offshore drilling after the explosion and sinking of the Deepwater Horizon rig last week. 
 
 The accident has led to one of the largest ever oil spills in U.S. water and the loss of 11 lives. On Wednesday federal investigators said the disaster is now releasing 5,000 barrels of oil a day into the Gulf, up from original estimates of 1,000 barrels a day. 
 
 U.S. regulators don't mandate use of the remote-control device on offshore rigs, and the Deepwater Horizon, hired by oil giant BP PLC, didn't have one. With the remote control, a crew can attempt to trigger an underwater valve that shuts down the well even if the oil rig itself is damaged or evacuated. 
 
 The efficacy of the devices is unclear. Major offshore oil-well blowouts are rare, and it remained unclear Wednesday evening whether acoustic switches have ever been put to the test in a real-world accident. When wells do surge out of control, the primary shut-off systems almost always work. Remote control systems such as the acoustic switch, which have been tested in simulations, are intended as a last resort. 
 
 Nevertheless, regulators in two major oil-producing countries, Norway and Brazil, in effect require them. Norway has had acoustic triggers on almost every offshore rig since 1993. 
 
 The U.S. considered requiring a remote-controlled shut-off mechanism several years ago, but drilling companies questioned its cost and effectiveness, according to the agency overseeing offshore drilling. The agency, the Interior Department's Minerals Management Service, says it decided the remote device wasn't needed because rigs had other back-up plans to cut off a well. 
 
 The U.K., where BP is headquartered, doesn't require the use of acoustic triggers. 
 
 On all offshore oil rigs, there is one main switch for cutting off the flow of oil by closing a valve located on the ocean floor. Many rigs also have automatic systems, such as a "dead man" switch as a backup that is supposed to close the valve if it senses a catastrophic failure aboard the rig. 
 
 As a third line of defense, some rigs have the acoustic trigger: It's a football-sized remote control that uses sound waves to communicate with the valve on the seabed floor and close it. 
 
 An acoustic trigger costs about $500,000, industry officials said. The Deepwater Horizon had a replacement cost of about $560 million, and BP says it is spending $6 million a day to battle the oil spill. On Wednesday, crews set fire to part of the oil spill in an attempt to limit environmental damage. 
 
 Some major oil companies, including Royal Dutch Shell PLC and France's Total SA, sometimes use the device even where regulators don't call for it. 
 
 Transocean Ltd., which owned and operated the Deepwater Horizon and the shut-off valve, declined to comment on why a remote-control device wasn't installed on the rig or to speculate on whether such a device might have stopped the spill. A BP spokesman said the company wouldn't speculate on whether a remote control would have made a difference. 
 
 Much still isn't known about what caused the problems in Deepwater Horizon's well, nearly a mile beneath the surface of the Gulf of Mexico. It went out of control, sending oil surging through pipes to the surface and causing a fire that ultimately sank the rig. 
 
 Unmanned submarines that arrived hours after the explosion have been unable to activate the shut-off valve on the seabed, called a blowout preventer. 
 
 Enlarge Image Close Agence France-Presse/Getty Images A welder in Port Fourchon, La., worked Monday on part of a dome that might be used to contain oil spilling from a well in the Gulf. 
 
 BP says the Deepwater Horizon did have a "dead man" switch, which should have automatically closed the valve on the seabed in the event of a loss of power or communication from the rig. BP said it can't explain why it didn't shut off the well. 
 
 Transocean drillers aboard the rig at the time of the explosion, who should have been in a position to hit the main cutoff switch, are among the dead. It isn't known if they were able to reach the button, which would have been located in the area where the fire is likely to have started. Another possibility is that one of them did push the button, but it didn't work. 
 
 Tony Hayward, BP's CEO, said finding out why the blowout preventer didn't shut down the well is the key question in the investigation. "This is the failsafe mechanism that clearly has failed," Mr. Hayward said in an interview. 
 
 Lars Herbst, regional director of the Minerals Management Service in the Gulf of Mexico, said investigators are focusing on why the blowout preventer failed. 
 
 Crude oil released into the Gulf of Mexico after an oil rig explosion last week is now threatening the Louisiana shore. WSJ reporter Angel Gonzalez takes a look at the damage from the air, where oil sheen seems to extend to the horizon. 
 
 Industry consultants and petroleum engineers said that an acoustic remote-control may have been able to stop the well, but too much is still unknown about the accident to say that with certainty. 
 
 Rigs in Norway and Brazil are equipped with the remote-control devices, which can trigger the blowout preventers from a lifeboat in the event the electric cables connecting the valves to the drilling rig are damaged. 
 
 While U.S. regulators have called the acoustic switches unreliable and prone, in the past, to cause unnecessary shut-downs, Inger Anda, a spokeswoman for Norway's Petroleum Safety Authority, said the switches have a good track record in the North Sea. "It's been seen as the most successful and effective option," she said. 
 
 The manufacturers of the equipment, including Kongsberg Maritime AS, Sonardyne Ltd. and Nautronix PLC, say their equipment has improved significantly over the past decade. 
 
 The Brazilian government began urging the use of the remote-control equipment in 2007, after an extensive overhaul of its safety rules following a fire aboard an oil platform killed 11 people, said Raphael Moura, head of safety division at Brazil's National Petroleum Agency. "Our concern is both safety and the environment," he said. 
 
 Related Article Oil Spill Estimates Raised Fivefold 
 
 Industry critics cite the lack of the remote control as a sign U.S. drilling policy has been too lax. "What we see, going back two decades, is an oil industry that has had way too much sway with federal regulations," said Dan McLaughlin, a spokesman for Democratic Florida Sen. Bill Nelson. "We are seeing our worst nightmare coming true." 
 
 U.S. regulators have considered mandating the use of remote-control acoustic switches or other back-up equipment at least since 2000. After a drilling ship accidentally released oil, the Minerals Management Service issued a safety notice that said a back-up system is "an essential component of a deepwater drilling system." 
 
 The industry argued against the acoustic systems. A 2001 report from the International Association of Drilling Contractors said "significant doubts remain in regard to the ability of this type of system to provide a reliable emergency back-up control system during an actual well flowing incident." 
 
 By 2003, U.S. regulators decided remote-controlled safeguards needed more study. A report commissioned by the Minerals Management Service said "acoustic systems are not recommended because they tend to be very costly." 
 
 A spokesman for the agency, Nicholas Pardi, said the decision not to require the device came, in part, after the agency took a survey that found most rigs already had back-up systems of some kind. Those systems include the unmanned submarines BP has been using to try to close the seabed valve. 
 
 —Jeff Fick contributed to this article. 
 
 Write to Russell Gold at russell.gold@wsj.com, Ben Casselman at ben.casselman@wsj.com and Guy Chazan at guy.chazan@wsj.com 
 
 Corrections & Amplifications: 
 
 The oil rig that exploded and sank in the Gulf of Mexico was owned by Transocean Ltd. and leased by BP PLC. A previous version of this article incorrectly said that BP owned the rig.
– The scope of the Gulf oil spill is far from clear, but the finger-pointing is already under way, and a lot of fingers ought to be aiming at Dick Cheney, Alex Pareene blogs for Salon. Connecting the dots that begin with a Wall Street Journal exposé, we learn that Cheney's highly classified energy task force was responsible for the fact "that the oil well didn't have a remote-control shut-off switch," Pareene writes, "a thing that it seems every single offshore drilling rig should have." "The former Dark Lord of the Naval Observatory" is no rookie at covering his tracks, but the follow-up argument is a no-brainer: "Halliburton is involved, too! The Los Angeles Times reports that BP contracted Dick Cheney's old company to cement the deepwater drill hole." In short, Pareene writes, "Thanks, Dick. Nice work."