Drilling developments

May 2002 Vol. 223 No. 5  Drilling Developments

Robert E. Snyder,  Contributing Engineering Editor

Steel BB drilling. ProDril Services, Inc. (PSI) of Cody, Wyoming, has developed a new drilling technique that increases the rate of penetration (ROP) and extends bit life. PSI conducted a series of field tests at the Rocky Mountain Oilfield Testing Center (RMOTC) out of Casper, Wyoming, ending in January, to demonstrate the process under different downhole conditions.

The PSI process adds steel shot (BBs) to the drilling mud system. The BBs enter the mud system through the surface equipment and are transported to the drill bit along with the mud. As the BB-laced mud hits the bit, it is subjected to a drastic increase in velocity at the drill-bit jet, and the steel shot hits the formation like sand blasting, which causes the formation to weaken. This allows the bit to cut through the weakened formation at a faster rate and increases ROP.

PSI says the tests at RMOTC proved the system can work. The surface system to deliver the steel pellets – two sizes were tested, 1/8 in. and 5/32 in. – was the biggest problem solved during these tests. The BBs are injected into the mud downstream of the pumps, and they are recovered in a proprietary gravity trap at the flowline for reuse. Questions of pipe and bit erosion were answered by positive tests on coated drill pipe joints, and bit inspection. Effects on electric logging were evaluated and proved negligible. BB concentrations used varied from 0.5 to 1.0% by volume. And the test operated successfully at the designated rig pressure at the test site of 2,600 psi, standpipe, although PSI says this can be as high as 4,000 psi.

The developer says significant ROP improvement was proved by the tests. Shot impact testing on rock samples at in-situ pressures is also done at PSI. It has been proven that multiple shot impacts improve the cutting, apparently as one BB fractures the rock and another helps break off more pieces. While formal reports from the RMOTC tests are forthcoming, further testing in a commercial well in the Rocky Mountain area has been scheduled. For more information, contact Hal Curlett, Tel: 307 527 4477; e-mail: hcurlett@prodril.com.

BP’s "consultant wedge." The March 2002 issue of BP’s monthly publication, Well Connected, is dedicated to the subject of "people." It contains a wealth of articles by BP engineers and managers on this important topic. The discussions and accompanying charts and tables supply valuable information. In one particular article by Glenn Fritchie, North American Wells Staffing Manager, the subject of the proportion of consultants used by BP for particular job disciplines is analyzed for the Houston area, and the percent of total personnel involved as consultants is reported as the "wedge."

For example, for Drilling engineers, the BP staff number is 82, the consultant staff is 11, and the wedge is 12%. The other three disciplines and the numbers are: Completion engineers, 82, 11 and 33%; Subsea engineers, 10, 12 and 55%; and Wellsite leaders, 102, 65 and 39%. The total is 222, 102 and 31%. Fritchie says the target range for consultant utilization is 30 to 40%, and is driven by the desire to develop / retain critical skills within BP. Above this range, he says, "We become exposed to loss of knowledge and organizational discontinuity resulting from consultant turnover. Below this range, we limit our ability to manage the down cycle without impacting our own employees."

Deepwater workshop May 29 – 31. Reading this item during the first week of May, or later, doesn’t give much planning time for an important event for offshore operators, but "better late than never."

Workshops sponsored by the Minerals Management Service (MMS) promote the dissemination and exchange of information about topics of concern relative to planned or potential Outer Continental Shelf (OCS) activities. In April 1997, MMS sponsored a workshop on environmental issues surrounding deepwater oil and gas development in the Gulf of Mexico. This workshop brought together experts from other government agencies, academia and industry that were tasked with identifying information needs in the physical, biological / ecological and social / economic sciences, as they related to industry’s recent and rapid advancement into the deeper waters of the Gulf. These discussions were then used as guidance in designing the MMS Deepwater Strategic Studies Plan composed of a series of deepwater studies.

With increased development of the deep waters of the Gulf, MMS must consider possible impacts to both the natural and human socio-economic environment. As industry gains more experience in deep waters, and studies better explain the deepwater environment, MMS seeks to again gather experts for a second Deepwater Workshop, scheduled for May 29 – 31, at the New Orleans Airport Hilton Hotel, New Orleans, Louisiana. To register online, try: www.mms.disl.org. For more information, contact: Gary D. Goeke at MMS in Pensacola, Florida, Tel: 850 433 2279; e-mail: gary.goeke@mms.gov.

Moving an island. In late February, Crowley Marine Services’ Energy and Marine Services business unit successfully moved the 312-ft square Concrete Island Drilling System (CIDS) Orlan from Prudhoe Bay, Alaska, to Sovietskaya Gavan in the Russian Far East for Sakhalin I Project operator, Exxon Neftegas Ltd., a subsidiary of ExxonMobil. The Orlan (ex. Glomar Beaufort Sea I) was purchased from Global Marine Drilling Co. and will be used for oil production as part of the Sakahlin 1 project, offshore Russia.

It was moved from its stack site near Northstar Island, off Prudhoe Bay, using two Crowley Sea Victory Class 7200 bhp twin-screw oceangoing tugs with more than 110-t bollard pull each. Arctic ice management was handled by Crowley, with a third tug contracted for the job, the 23,200-bhp Arctic Kalvik. Orlan has a 34-ft draft and comprises four basic components – steel mud base, concrete brick caisson, and two steel deck barges on which the rig, support equipment and quarters are mounted.

On September 4, 2001, the team set up the three tugs for the tow. A little over a month later, on October 14, Orlan was delivered, cleared through customs and arrangements to lower it in the harbor were made. The team had to do some dredging to make room for the vessel, which is about 60-ft deep with its mudskirt, before lowering it to its new position on the bottom.