GEOSCIENCES
Interim East China Sea seismic data points toward Lishui gas play
Primeline Energy Holdings Inc. has completed acquisition of 3D seismic covering 550 km2 (212 mi2) from block 25/34 in the East China Sea and has started processing the data after merging them with an existing 233 km2 (90 mi2) of 3D data captured earlier. Processing is expected to be complete at the end of 1Q 2007. The survey aims to define the Lishui 36-1 gas discovery and to help site one or two more wells to help determine commerciality. Primeline says the locations will be selected in March or April and drilling will begin as soon as possible once a rig is located. The tight rig market may delay drilling, the company says.
The Lishui gas discovery consists of two wells that have flow rates of 9.9 MMcf/d and 12.6 MMcf/d of natural gas, respectively. Block 25/34 encompasses 7,006 km2 (2,705 mi2) in the basin where seven previously drilled wells encountered oil and gas.
Primeline holds a 75% interest in the block 25/34 with China National Offshore Oil Corp. Primeline is the operator.
Falklands surveying continues
Offshore Hydrocarbon Mapping Plc. has begun a controlled source electromagnetic (CSEM) survey over Falkland Oil and Gas Ltd. prospects. OHM will use its survey vesselCS Teneo, to acquire a series of CSEM lines over FOGL’s 20 top prospects and leads off the Falkland Islands.
In late 2006, the Wavefield InSeis AS vesselBergen Surveyor began a 2D program that is to cover 10,000 line km (2,614 mi) over FOGL’s 2002 and 2004 licences. More than 3,000 km (1,864 mi) of data have been acquired to date. Results from the CSEM survey will be used to assist in planning the later stages of the 2D seismic survey.
It is intended that a close spaced, 1 km x 1 km (0.62 mi x 0.62 mi) seismic grid will be acquired over the most promising prospects identified by CSEM to determine drilling locations.
The seismic survey is expected to take until mid-year to complete. Processing and interpretation of both the 2D and CSEM surveys is expected to take up to six months to complete.
Rockhopper Exploration Plc. has completed interpretation of 920 km (572 mi) of 2D seismic data in combination with CSEM data previously taken north of the Falkland Islands. Based on the results, Rockhopper has increased its reserves estimates for the Ernest prospect by 30% to 130 MMbbl. Also, on Lead K, results indicate possible recoverable reserves of 60 MMbbl.
As a result of the work, Rockhopper says Ernest can be mapped at multiple levels, with at least two zones of interest from a depth of about 980 m (3,215 ft) to 2000 m (6,562 ft). According to the company, CSEM data over Ernest shows a single discrete resistor on Line 1 (east/west) at approximately 1,500 m (4,921 ft). This is coincident with the deeper closure mapped on the seismic. The CSEM data over Ernest also shows two discrete resistors on Line 2 (north/south). One appears to be at the deeper level and is coincident with the resistor. The second appears to be shallower and coincident with a separate closure, still part of Ernest, at approximately 1,100 m (3,609 ft). Rockhopper reports an amplitude versus offset anomaly on the flank of Ernest at the shallower level which is coincident with the CSEM response.
“The information provided by the interpreted seismic is highly encouraging,” says Sam Moody, Rockhopper managing director. “The two areas covered by CSEM have been further defined with the new seismic data, and we have a significant number of leads to examine in licences PL023 and PL024.
“As previously announced, we have just completed the acquisition of 3D seismic in our northern licences PL032 and PL033 and are on course to developing a number of drillable prospects by the third quarter of 2007.
“During the last 12 months, we have successfully acquired 2D, 3D, and CSEM data and have significantly progressed our exploration portfolio as a result.”
FOGL describes the general area geology as four major sedimentary basins: the Falkland Plateau to the east, South Falkland to the south, the Malvinas to the west, and North Falkland to the north.
The four basins appear to have extended initially as Triassic through earliest Cretaceous rifts associated with the break-up of Gondwanaland. An early cretaceous (Valanginian) end to rifting was followed by thermal sag. There is evidence of Tertiary uplift, possibly coincident with Andean compression and the development of overthrusting along the plate boundary to the south of the Islands resulting from opening of the Scotia Sea.
Norwegian survey work likely to increase
Hydro, Pertra, Statoil, and Talisman Norge have contracted Fugro to conduct 3D seismic surveys offshore Norway this summer. The combined value of the contracts is more than $50 million, Fugro says.
That was before the Norwegian oil ministry offered a record 48 exploration licenses for 85 offshore blocks under its Awards in Predefined Areas program.
The award was for 34 licenses in the North Sea, 12 in the Norwegian Sea and two in the Barents Sea, in Arctic waters that Norway sees as key to maintaining its oil flows in the future.
“It is important to develop the Barents Sea as a petroleum province,” says Norwegian Oil Minister Odd Roger Enoksen. He says the predefined area system provides opportunities for new, smaller oil companies on the Norwegian continental shelf. Eight of the 33 companies offered shares on the new blocks were new to Norway.
The oil ministry said companies that were offered operatorships included BG Norge AS, Centrica Resources Norge AS, Norske ConocoPhillips AS, Endeavour Energy Norge AS, E.ON Ruhrgas Norge AS, Gaz de France Norge AS, Lundin Norway AS, Nexen Exploration Norge AS, Norsk Hydro Produksjon AS, NORECO AS, OMV Norge AS, Pertra AS, Petro-Canada Norge AS, Premier Oil Norge AS, Revus Energy AS, RWE Dea Norge AS, Statoil ASA, Talisman, and Total E&P Norge AS.
PGS charters SeaBird’s Harrier Explorer
PGS has entered into a four-year time charter with SeaBird Exploration Ltd. for theHarrier Explorer as a fully equipped and operated source vessel. PGS has the option to use the vessel for 2D surveys by covering the cost of additional seismic equipment and additional operating cost. The contract value for the firm period is $58 million and is to begin on May 1 with two one-year extension options.
JSX reports Thai data reprocessing results
JSX Energy has received the results of CGGVeritas’ reprocessing of seismic data from Mae Sot block L17 in Thailand.
JSX has hired Petro-Ventures International to interpret the new data, and final results are expected in a few weeks.
Upon initial review of the reprocessing results, Petro-Ventures senior geophysicist Carl Goldwater says “The stratigraphy observed on portions of Mae Sot seismic data is very similar to that of the hugely productive lacustrine section of the Phitsanulok basin.”
Goldwater has conducted several surveys of Mae Sot and of the Phitsanulok basin, which are next to block L17.
Al-Khafji JV awards seismic work to Fugro
The Al-Khafji Joint Operations has awarded high density 3D and regional 2D marine seismic data acquisition and processing to Fugro.
Scheduled to start in April, Fugro will execute the $38 million contract using its seismic vesselGeo Baltic. Duration of the project is for as much as a year.
Al-Khafji is a joint venture between Aramco Gulf Operations Co. Ltd. and Kuwait Gulf Oil Co. off Saudi Arabia.