On the subject of coring (from HDR's website)CoreA sample,...

On the subject of coring (from HDR's website)

Core
A sample, usually of reservoir rock, taken while drilling a well. Cores are drilled with a core bit, in conjunction with a core barrel and core catcher. The core bit has a hole in its centre which allows the bit to drill around a central cylinder of rock, which is taken in through the bit and into the core barrel. The core barrel stores the rock core and the core catcher serves to grip the bottom of the core so that it does not fall out the bottom of the drillstring while it is being pulled out of the well.

Core samples are used for many studies which have an impact on the volume of reserves and the likely productivity of an oil or gas field. In some instances cores may be taken over longer intervals than the hydrocarbon bearing zone in the well being cored to gain information of use across the whole field.

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Also to those who'd like to chew on HDR's prospects

The Stampede for West African Oil - 15/08/2002
Sierra Leone and Mauritania show the on-going rush by international oil companies to build up the booming West African oil and gas fields
By Kofi Akosah-Sarpong
Day in, day out international oils firms are scouting the West African sub-region, touted as the world's most endowed oil and gas region, for exploration, production and deals. Diamond-rich Sierra Leone and Mauritania are the latest of the countries in West Africa to experience oil talks and explorations. Recently, the Sierra Leone government co-hosted meeting with Texas, USA-based TGS-NOPEC Geophysical Company in London, U.K. and Houston, U.S.A to announce the upcoming offshore bid round.
The Houston meeting attracted 28 oil and gas companies, which included both independents, and major companies. TGS-NOPEC is a leading global provider of non-exclusive seismic data and associated products to the oil and gas industry. Oil companies use this seismic data to explore for and develop oil and gas deposits. TGS-NOPEC specializes in the planning, acquisition, processing, interpretation, and marketing of non-exclusive surveys worldwide. The company places a strong emphasis on providing high quality seismic data and the highest level of service to the industry.
TGS-NOPEC also offers proprietary seismic acquisition and processing services, as well as gravity and aeromagnetic surveys. Recent interest in the offshore Sierra Leone area has grown due to the successful drilling in Cote d'Ivoire (Baobab Discovery) in the south, in Ghana (Tano basin) in the south, and in Mauritania (Chinguetti-1) to the north. Freetown is offering approximately 28,000 square kilometers (sq kms) of the offshore area for lease by oil and gas companies to develop the petroleum reserves of the country.
The concession areas are split into 7 blocks, each approximately 4,000 sq kms. The bid round will remain open through March 30, 2003, at which time all bids are due. TGS-NOPEC has acquired 5,700 kilometres seismic data in preparation for the bid round. The new data was acquired with long offsets to image the deeper subsurface. The data has been processed with state of the art pre-stack time migration. In addition, the logs for two wells and a regional interpretation report are available. Analysts argue that the bid round has been made possible by the Sierra Leone General Election in May, 2002 and subsequent implementation of a new Model Petroleum Agreement (Royalty-Tax Concession Agreement).
Either because of the memories of the just ended diamond-induced civil war, or the fact that an official announcement of a discovery of oil during the civil war would have prolonged the war, in view of fact that natural resources are analyzed to induce most of the conflicts in Africa, Freetown has downplayed for long the fact that Sierra Leone is endowed with oil. Now after the end of the civil war, which saw the Revolutionary United Front battling various governments in the country and which was accused of being influenced by diamonds than any revolutionary zeal, Freetown is coming clean about prospects of Sierra Leone having oil offshore. In fact, some commentators argued that as far as 1962 the story of Sierra Leone having oil have been shrouded in mystery ever since the country gained its independence from Britain in April 1961. "Nevertheless, despite the institutional secrecy surrounding this potential source of wealth creation for our country, it is now beyond all dispute and doubt that there is oil in Sierra Leone.
However, the location, extent, and quality of the find have remained a subject of uninformed speculation, intense curiosity, and often-wild conjecture. It is a state of affairs to which both official secrecy and the lack of transparency in the conduct of public affairs in Sierra Leone have largely contributed," wrote a Sierra Leonean analyst. Clearing the air about the controversy that Sierra Leone has oil potential, Dr. Sama Banya, a former senior presidential adviser to President Ahmed Kabbah, had told the Freetown-based Concord Times that "the prospects for oil are very strong and that all the indications are that we have oil, and we do not only have oil, we have it in commercial quantity." Prospecting for oil is expected to start in either in 2003, 2004 or 2005. "It is a long process especially since it is not onshore, it is offshore," said Dr. Banya. Despite Dr. Banya's statements, controversy abounds in the country whether Sierra Leone has oil, but Deen Swarray, the Minister of Resources, has said, "We do not know if we have oil. It is yet to be discovered." Kabbah, whose government is reported to have spent US$3 million on oil exploration, is reported to want oil exploration to be done by oil companies and not government.
As the climate of impending oil boom in West Africa gains grounds and many West African countries including Sierra Leone diagnosed to have oil potential, Freetown has opened up its oil secrecy, putting the wild speculation at rest by announcing that the government has set up a programme to renew oil exploration. According to a government press release, the first exploratory well will be drilled between February and July 2003, and if it were successful, a second exploration well would be drilled between July 2003 and July 2004 to determine the commercial production capacity of the field. "If this too is successful, the installation of production facility will then follow to facilitate production by January 2005," the government had said.
Two exploratory oil wells were drilled in shallow waters of the country in the early 1980s by AMOCO Sierra Leone Exploration Company Limited, a member of the Standard Oil Indiana Group but were said to be not commercially viable then. Freetown argued that the exploration for oil is a long-drawn-out and grueling process, "but which when successful would transform the country." How this will be different from what obtains in the appalling diamond regime is yet to be seen as the petrodollar rolls in. In the arrangement for the renewal of the oil exploration programme, a new petroleum law relating to oil and gas activities has been hammered to set the stage for oil companies to bid for the commercial exploitation of oil. Freetown intends to advertise the Bid Round internationally soon, oil and gas watchers say.
TGC-NOPEC has carried a six-week offshore survey in the ocean around the southern areas of Sierra Leone's Pujehun, Sulima and Bonthe and found commercial quantity of oil. But the Sierra Leonean oil watchers fear trouble brewing between Freetown and Monrovia since the southern areas where the oil and gas lie, especially Bonthe and Sulima, are very close to Liberia. A senior government official in Freetown has been quoted as saying: " There is evidence of oil and gas in fairly large quantities in up to 3,000 metres of water." TGS-NOPEC is expected to handle the bidding round on behalf of the Freetown. The oil industry is also an important sub-element in the economy of the country. The Sierra Leone Oil trouble lies somewhere else: the prospects are off the island of Bonthe and Sulima, very close to the border with Liberia. For many years, Liberia, too, has been scheming to draw plans to sell oil blocks close to the Sulima area.
If Sierra Leone is battling to join West Africa's oil and gas club, Mauritania is seeing international oil companies falling over each other for its piece oil and gas. Mauritania has no proven hydrocarbon resources but there is potential for offshore oil and international oil companies have been involved in exploration. In 1998 Hardman Petroleum, in partnership with Dana Petroleum (operator), Woodside Petroleum and British Borneo Oil and Gas were awarded concessions offshore Mauritania.
In June 2000, Dana Petroleum stated that they had identified a number of significant hydrocarbon leads in both shallow and deepwater prospects in blocks 1, 7 and 8. This is a Dana (80 percent), Hardman (18 percent) venture with a work programme that began in mid 2000 with a 4,000 to 5,000 kilometre 2D seismic survey. Elixir Corporation's 2 percent is currently carried by Hardman, but their interest will transfer to any farm-in partners. As no hydrocarbon discoveries have been made, Mauritania has no production. Even so, a tiny oil field is attracting some of the world's biggest oil companies into the little-explored seas west of Mauritania.
Oil and gas companies from Italy's Agip, Australia's Woodside and Houston's Amerada Hess are amongst the jamboree of companies rushing into the Mauritanian oilfields. Other oil and gas firms are partnering to a get a piece of the Mauritanian oil pie. Anglo-Australian Fusion is said to be putting the final touches to a new agreement with Amerada. The scheming and partnering going in Mauritania by international oil companies, analysts say, indicate the prospect that there is a growing hope that Mauritania may prove to be as lucrative as other hotspots of oil activity in Africa such as Angola and Nigeria. "We feel confident that there are commercially viable opportunities in Mauritania…Now we've got to translate that feeling into fact," said an official of Fusion, which undertaking seismic exploration for some of the big international firms on the Mauritanian coast. Fusion is drilling at a key well in offshore Mauritania with the help of Woodside and Agip. International oil firms prospecting for oil on the Mauritanian offshore are informed by signs seen in such West African states like the Gambia, Senegal, Guinea Bissau, Ghana and Gabon despite little proof of any benefits. Enormous oil reserves have already been discovered in Angola and Equatorial Guinea.
Woodside Petroleum Ltd announced that it is planning a drilling program offshore Mauritania during the third quarter of this year. The company hopes that this program will pave the way for Mauritania's first oil production. Woodside chairman Charles Goode said the company had started development planning associated with its first international oil discovery, 90 km off the Mauritania coast. Goode said the exploration and appraisal drilling campaign in the greater Chinguetti area would be a major influence in determining the scope and timing of any commercial development.
Following guidance from the Mauritanian Government, all wells in Mauritania will now follow the naming convention "Chinguetti-Block number-Well number". Therefore, the official designation of this well will be "Chinguetti-4-2". As of August 7, Chinguetti-4-2, the first well in a multi-well 2002 drilling programme offshore Mauritania, was drilling ahead in 12(1/4) hole at 1,896 metres. Chinguetti oil got their first discoveries ever in 2001.
Woodside Mauritania Pty Ltd, Operator of the Mauritania PSC B Joint Venture, reports that the Chinguetti-4-2 step-out exploration well, located in Block 4 offshore Mauritania, 2.5 kilometres north of Chinguetti-1, spud on July 30. The location is approximately 85 kilometres northwest of Nouakchott, the capital of Mauritania; water depth at the location is 815 metres. The planned total depth is 2835 metres. The drill ship "Deepwater Discovery" is drilling the well. "Success here would be a particularly exciting outcome as it would most likely result in Mauritania's first oil production and the first Woodside-operated international oil production facility," Goode has said. Woodside is planning to spend US$106 million on exploration this year, targeting Australia, West Africa and the Gulf of Mexico. The Woodside operated Chinguetti-1 well offshore Mauritania last May found a gross 90 meter gross oil column, sparking speculation that a major new oil province had been discovered. On July 19, Woodside Petroleum Ltd and Hardman Resources Ltd resume drilling in Mauritania, more than a year after their wildcat Chinguetti discovery.
As oil prospects brighten, a drilling rig has arrived in Mauritania to drill the first of a three to five well program, the Chinguetti 4-2 appraisal well. Located on the northern flank of the Chinguetti salt structure, the well is only 2.5 kilometres north of the Chinguetti-1 discovery well, which was drilled in May 2001. Shares in both companies surged after it intersected several oil-bearing sandstones in the main target zone over a gross hydrocarbon interval of 86 metres. However, the project suffered a setback in July 2001 after the much-anticipated Courbine well failed to match the success of Chinguetti. Woodside said earlier this year its "objective in Mauritania was to fully test its prospectivity and establish commercial volumes." Other joint venture participants in the project include ENI Agip British Borneo Ltd, Fusion Oil and Gas and Roc Oil.