Lower Tertiary play calls for new technology
Baker Hughes Inc. has completed its acquisition of BJ Services Co. This reduces the number of major stimulation vessel operators by 25%, and makes the combined company the second largest vessel operator.
The last step came when Baker and BJ agreed with the Antitrust Division of the US Department of Justice to divest after the merger two stimulation vessels and “certain other assets used to perform sand control in the Gulf of Mexico” which were not named specifically. The two vessels are Baker Hughes’HR Hughesand BJ Services’ Blue Ray. This agreement also contained a Proposed Final Judgment and a Hold Separate Stipulation order.
Since both companies already garnered shareholder approval for the action, the deal became complete.
“With the completion of the BJ Services merger, we have filled an important gap in the products and services we offer our customers,” said Chad C. Deaton, Baker Hughes chairman, president, and CEO. “The process of integrating our companies begins immediately for the corporate staff and for operations outside of the US. In the US, we have agreed with the Department of Justice to operate BJ Services and Baker Hughes separately until the required divestiture is completed, which we expect to be finalized in the next several months.”
Pending the merging of the two companies in the US,Offshore has chosen to list the two companies separately for this survey. Once the melding is complete, the survey will be updated online and, of course, in subsequent years.
In action separate from the acquisition, BJ Services retired theChallenger and Discovery from active duty. Baker Hughes added the Blue Tarponto its fleet.
Elsewhere on the vessels front, both Halliburton and Schlumberger added a new asset and retired an older one. Halliburton brought theNormand Vesterinto service and dropped the War Admiral from its list. Schlumberger added the DeepSTIM Mexicoand took off the Galaxie.
Once all the changes are tallied, the worldwide list contains a total of 31 vessels, adding three to the 2009 list while deleting four, a net change of minus one.
Downhole technology
Gulf of Mexico discoveries in the Lower Tertiary have driven innovations in both the downhole stimulation technology and in the vessels that deliver that technology.
In the past, typical continental shelf and Miocene pays have been 100 ft (30 m) or fewer intervals with shale separation. The Lower Tertiary tends to have permeabilities in the 10-50 md range with long, continuous pay zones up to the 300 ft (91 m) range. As a result, the offshore stimulation can require multi-zone, single-trip fracturing strategies taken from onshore shale plays. Fracturing fluid has to be denser because the wells will have high fracture gradients. It is necessary to use high-density fluids to reduce surface treating pressures. Also, fracing long intervals requires high pump rates from the vessel that push the limits of available systems.
While the power to pump might be available, the 15,000 psi and more surface treating pressures bring in HSE concerns for vessel personnel. Also, such pressures stretch the limits of marine risers and casing below the subsea wellhead should there be a shallow leak in the string. Bringing fluid specific gravity up can reduce the required pump pressure if the well conditions permit.
“Our customers in the Lower Tertiary play routinely encounter depths below 20,000 ft (6,096 m) and pressures above 20,000 psi, making it is necessary to use high-density fluids for reducing surface treating pressures,” says Richard Vaclavik, GoM Region vice president, Halliburton. “Due to the nature of the Lower Tertiary’s Wilcox formation, fracture stimulation is required and our high-density fracturing fluid technology is a key enabler for successful treatments.”
As an example of the vessels designed to provide this service, BJ’s recent launch theBlue Dolphin is designed to provide 20,000 psi (138 MPa) working pressure via multiple reeled flexible umbilical lines. It can perform large-volume, high-pressure stimulation operations for multi-zone or multi-well operations.
The vessel features a DP-2 dynamic positioning system and is equipped with eight skid-mounted 3,000 bhp fracturing units and storage capacity for 2.75 million lb of proppant. It can provide up to 23,000 hhp and 80 bbl/min (12.7 cu m/min) blending rates to meet high-rate fracturing and stimulation requirements of ultra deepwater projects. Measuring 300 ft (91 m) in length, the multipurpose vessel includes additional storage for up to 11,800 bbl (1,875 cu m) of fluids or completion brines, 12,600 gal (47.7 cu m) of raw acid, and 6,300 gal (23.8 cu m) of solvent.
The GoM is not the only market for stimulation vessel service, of course. Another region with similar operating conditions is found off West Africa.
Looking at the total offshore operations and maintenance spending total over the next five years, Douglas-Westwood predicts it will reach more than $330 billion. Of this total, production services will dominate the O&M market, which itself is expected to outgrow other sectors.
