That "tens of billions of barrels" estimated by Azad in his Oil & Gas Journal Article for the Coastal Petroleum Leases is beginning to look like the entire rest of the Gulf of Mexico in terms of potential quantities. I don't know if Azad's projection is realistic or wild hype, but I'd sure like to find out. And we don't need to advance the state of the deep drilling art to find out:
HoustonChronicle.com -- houstonchronicle.com | Section: Business
April 27, 2001, 6:31PM
Offshore technology finds deepwater oil; getting it to shore a problem
By NELSON ANTOSH
Copyright 2001 Houston Chronicle
The industry wisdom is that 10 billion barrels of oil have been discovered in the Gulf of Mexico, but only 3.6 billion barrels have been developed thus far.
There is theoretically another 30 billion barrels yet to be discovered, virtually in our own back yard, with high prices a great lure for the oil companies.
But when it comes to deep water, the ability to find oil is outracing the industry's ability to get it out of the ground and to shore.
While drillers are talking about going into waters 10,000 feet deep, production is limited to about half that depth. The current record for producing oil and gas in the Gulf is 5,300 feet, held by Shell at its Mensa field.
The shallow portions of the Gulf have been drilled so much that the biggest finds are likely in the deep water, making this area stand out as the nation's last frontier for large-scale oil and gas production.
The latest developments to move production into these deep waters will be a big part of the draw for the Offshore Technology Conference, a world event that opens Monday in the Reliant Astrohall and continues through Thursday.
At least 1,800 companies will be manning displays of their equipment, from underwater robots to mooring lines, for the benefit of around 43,000 visitors.
The topics of the sessions show the wide range of difficulties presented by deep water. Anything below 1,000 feet is considered deep, but in this case ultradeep is considered to be between 5,000 feet and 10,000 feet.
There are problems with flow lines becoming clogged by the cold, questions about powerful water currents, and overall the need to control huge costs. The crushing pressures of more than a mile of water and working in the blind depths create enormous difficulties.
Oil-field services company Halliburton on Monday will outline an agreement for developing a new level of robot for working in deep water. Those depths are far greater than any diver could withstand.
And Shell International Exploration and Production will show its solution to vortex-induced vibration, a phenomenon that causes pipes and even platforms to shake when water flows by.
As the water gets deeper, there is more pipe exposed to the current, which also tends to get stronger than if close to shore.
The executive vice president of Transocean Sedco Forex will describe the past year's experience of providing BP with the world's largest drillship, capable of doing two different jobs at once -- an important cost-cutting measure for a vessel costing around $250,000 a day to lease.
There also are environmental barriers to finding and producing oil from the depths.
A senior scientist with Geco-Prakla will describe industry efforts to produce whale-friendly seismic noise.
There is considerable worry by environmentalists that noise in the oceans, including that produced by the seismic equipment used to look for oil and gas, affects whales. The U.S. Marine Mammal Protection Act is is scheduled for renewal this year.
That's just the beginning.
About 300 technical papers will cover topics from analyzing splicing methods for linking synthetic mooring lines to the effect of hurricanes on floating production and offloading vessels. The industry wants to use these in the Gulf of Mexico.
Getting at the oil and gas in ultradeep water requires "step changes" in technology, plus more collaboration between companies, according to a trio of companies that will in June perform the world's deepest well completion.
BP, Schlumberger and Transocean Sedco Forex will install what is called a wet tree in 6,975 feet of water in BP's King's Peak field about 150 miles southeast of New Orleans.
That would beat the current deepest completion, at 6,250 feet, off the coast of Brazil, which uses a conventional subsea Christmas tree.
The effort will involve Transocean's Discoverer Enterprise, a huge drillship that can do multiple underwater tasks at the same time, and Schlumberger's new SenTree Christmas tree, which is electrically activated.
The speed of this electrical activation is crucial because a quick disconnect prevents the subsea equipment from being pulled apart or broken should the ship move.
The tree and its Commander control system are able to shut the valves and unlatch from the blowout preventer within 15 seconds, according to Michael Frugé, a testing and sales engineer with Schlumberger.
A quick disconnect is needed when working from a vessel that is dynamically positioned over the well using thrusters. Mooring it to the bottom with cables is impractical in such depths.
Although there are backups to the engines that power the thrusters, there remains a fear that something could happen that would allow the ship to drift.
The typical three to four minutes to disconnect using hydraulic lines from the surface is too long, according to J. Rodney Hensley, the wells delivery team leader for BP. This hydraulic response is slow because the hose balloons as the pressure moves downward, Hensley said.
With the Schlumberger equipment, which was developed over a period of years with the help of BP, the pumps and the hydraulics are at the bottom of the Gulf.
Within approximately 10 seconds, these pumps close a ball valve, a flapper valve, and a retainer valve to keep the contents of the pipe leading to the ship from spilling into the water. Then a latch opens, which releases the pipe from the tree.
The SenTree has been used only a few times with conventional hydraulics, Frugé said. It is designed to work to 10,000 feet.
It was used electrically for the first time in BP's Nile field in 3,450 feet of water. The recent installation was a "beautiful" completion, said Hensley of BP.
Such completion work is tricky. It involves a lot of finesse and is closer to science than drilling a well, says Lou Tapscott, executive vice president of Cal Dive International of Houston. His company does a lot of deep-sea work.
Oil production tends to be slow to come on line, as companies drill more wells to outline the field and then go through the engineering process. This "gestation period" between the time oil is found in the deep Gulf and the time production actually begins can be 10 to 12 years, Tapscott said.
To take advantage of increasing offshore activity, Cal Dive is building a unique semisubmersible vessel that isn't expected to ever drill a well. It has a big deck that will be used for construction jobs such as installing subsea trees, laying pipe, and doing downhole well servicing.
The Q4000 is being built at the Amfels yard in Brownsville, with completion scheduled in June or July, and sea trials expected to begin in August. |
