Ever since that fateful night in the Gulf of Mexico when deepwater driller Transocean's (NYSE: RIG) Deepwater Horizon rig exploded into an inferno that led to 11 deaths and a massive underwater gusher, we've tended to refer to the event as the BP (NYSE: BP) spill.

But there have been those who have consistently doubted the accuracy of that moniker. For instance, as The Wall Street Journal observed in its weekend edition, cementing, which is vital to the safety of drilling oil or natural gas wells, is hardly immune to failure. As the Journal also noted, "A study of incidents between 1992 and 2006 found that cementing was the single largest contributor to Gulf of Mexico blowouts, playing a role in 18 of 39 incidents."

Cement, you're up
So, cement has reemerged as a possible reason why the Deepwater Horizon, which was drilling BP's Macondo well, met with such a violent end last spring. The cementing of the well was provided by Halliburton (NYSE: HAL), the second-largest oilfield services company and the biggest factor in the cementing portion of the business.

Late last week, a National Oil Commission report said that cement tests conducted at a Chevron (NYSE: CVX) facility have indicated that the cement used by Halliburton may have been unstable and faulty. Specifically, it said that testers were unable to generate stable foam cement using Halliburton's materials. The company immediately rebutted the tests, saying that they did not include the actual supplies used or properly replicate the conditions at the well.

Halliburton has now been ordered by U.S. District Judge Carl Barbier of New Orleans to provide "certain materials" used in its work on the Deepwater Horizon to U.S. Coast Guard and Department of the Interior investigators. The order further requires that "no destructive testing on the cementing components will be conducted without further order of the court."

Also last week, a spill commission revealed that Halliburton had conducted four tests on the cement to be used on the Macondo well, and that only one indicated that the cement was likely to hold. Halliburton has blamed BP for altering the mix at the last minute and has admitted that it therefore did not perform a stability test on the final cement composition.

And next up: Anadarko
But Halliburton isn't the only company receiving new marching orders from investigators. Anadarko Petroleum (NYSE: APC) has been subpoenaed to turn over to investigators seven sample boxes containing Macondo drilling cuttings by this Thursday. Anadarko is a 25% partner with BP in the well. However, given its apparent belief that BP may have been grossly negligent in causing the spill, it has refused to participate with the British company in compensating the spill's victims.

Shear confusion
Before we rush to judgment with guns a-blazing at Halliburton or BP, however, the rig's blowout preventer (BOP) shouldn't be dismissed from the list of potentially causal items. After all, this massive five-story, 300-ton fire hydrant on steroids utterly failed to function during the disaster.

All manner of contention has emerged regarding why the BOP's "shear arm" failed to chomp through the drill pipe to shut down the well after the methane had reached the rig and further damage had been done. For instance, both BP and Transocean have maintained that the BOP's manufacturer, Cameron International (NYSE: CAM), had not approved some maintenance and repairs during the life of the unit, thereby possibly contributing to its malfunction.

Spreading the blame
Despite the incessant carping about well design, cement, the condition of the BOP, and a host of other considerations, we may eventually discover that the Deepwater Horizon disaster actually resulted from a variety of factors, and that no one company can or should be held singularly at fault. As such, and given my belief that energy commodities prices and equipment demand are destined to rise sooner than we think, I'd urge Fools not to consciously avoid plunking down shekels for any of the companies named above.

Beyond that, because both the need for offshore equipment and the stringency of the rules governing its design are likely to increase in the months and years ahead, I'd also include systems and components manufacturer National Oilwell Varco (NYSE: NOV) on my shopping list for the increasingly important energy sector.