Log Data Confirms Wei-6-12S-1 Discovery
Roc Oil says log data, including pressure and sampling information, most recently acquired from the Wei-6-12S-1 exploration well, offshore China, confirm three separate gross hydrocarbon columns with individual gross thicknesses of 65 meters, 111 meters and 121 meters, which collectively represent 95 meters of total net hydrocarbon pay, including 80.5 meters of net oil pay.
Two of the three oil columns appear to extend beyond the structural closure as presently mapped.
An appraisal program consisting of at least two production tests through liner and the drilling of at least one sidetrack well, is expected to commence immediately, subject to equipment availability.
As of May 17, 2006, the Wei-6-12S-1 offshore exploration well in Block 22/12 in the Beibu Gulf, offshore China, had run and cemented 7 inch liner to 2,521 meters below rotary table ("mBRT"). The current operation was preparing to drill ahead in 6 inch hole to a revised Total Depth of 2,615 mBRT.
Prior to running the liner, a wireline logging program was undertaken which included the gathering of pressure data and the retrieval of fluid samples. Although the final stages of the pressure testing and sampling aspects of this program had to be curtailed due to the need to secure the hole ahead of the possible arrival of Typhoon Chanchu, the bulk of the logging program was undertaken as planned.
Technical analysis of all the well data continues but final definitive results will not be available for several weeks. Therefore, what follows should be regarded as an interim interpretation of the well results details of which may be subject to refinement as additional information is gathered and analyzed. In this context, the main point to note is:
Between 1,947 mBRT and 2,450 mBRT there is a sand-shale-silt sequence which has a gross thickness of 503 meters. There are three main sand packages within this sequence – top, middle and lower – all of which contain oil. The total gross thickness of these three sand packages is 477 meters, of which 154 meters is net sand. Three separate hydrocarbon columns are present with a total gross thickness of 297 meters of which a total of 95 meters is regarded as net hydrocarbon pay with reservoir porosities averaging about 20%.
The upper part of the Top Sand package has a gross hydrocarbon column of 50 meters and a net hydrocarbon pay of 14.5 meters (29% Net: Gross). Although the electric logs through this section do not display any obvious gas effect the pressure and fluid sampling program indicates that the hydrocarbon type in this part of the section is gas.
The lower part of the Top Sand package has a gross hydrocarbon column of 71 meters and a net oil pay of 14.5 meters (20% Net: Gross). Oil samples were recovered from this section.
Currently, these two gross hydrocarbon columns are considered to be in a single pressure regime and as such are regarded as a single gross column.
The well did not define an oil-water contact within the Top Sand package. The weight of currently available evidence suggests that this contact is located some distance down dip, apparently below structural closure, as presently mapped.
The Middle Sand package has a gross hydrocarbon column of 65 meters of which 31 meters (48% Net: Gross) is regarded as net hydrocarbon pay, specifically oil. Based on preliminary analysis of samples recovered from this sand package the oil is light, mobile and non-viscous. The well penetrated an oil-water contact within this Middle Sand package which is below the structural closure, as presently mapped.
The Lower Sand package has a gross hydrocarbon column of 111 meters of which 35 meters (32% Net: Gross) is regarded as net hydrocarbon pay, probably oil, although an associated gas cap also may be present. This interval was not sampled because the sampling program had to be curtailed due to the approach of Typhoon Chanchu. Therefore, comments as to the fluid type in this part of the well are based on log interpretation and oil shows observed while drilling and as such are subject to confirmation by sampling and/or testing.
The Block 22/12 Joint Venture has decided that the Wei-6-12S-1 well merits a thorough and immediate appraisal program. The details of this program are currently being discussed with all interested parties, including relevant government authorities. Presently, the appraisal program is expected to include at least two production tests through liner and the drilling of at least one sidetrack well. Subject to sourcing the relevant equipment this phase of operations is expected to be carried out during the next several weeks. The next Stock Exchange Release will further detail the appraisal program and is expected to be issued next week.
Commenting on the interim results of the well, ROC's Chief Executive Officer, Dr. John Doran stated that:
"The latest results support ROC's previously announced 'cautious optimism'.
The presence of gas in the uppermost part of this very thick sand section, although a surprise, is unlikely to be too significant in the overall scheme of things, particularly if there is an associated oil leg down dip.
The apparent extension of two of the three oil columns down dip beyond structural closure, as presently mapped, needs to be investigated thoroughly, because, if it is confirmed, the implications could be quite significant.
At this stage of exploration, it is always better to gather more data rather than speculate - and that is exactly what our immediate appraisal program is designed to do".
The Block 22/12 Joint Venture is comprised of Roc Oil (China) Company as operator with 40%; Horizon Oil with 30%; Petsec Energy with 25%; and Oil Australia with 5%;The China National Offshore Oil Company ("CNOOC") is entitled to participate up to a 51% funding equity level in any commercial development within Block 22/12.
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