(Corallian Energy Limited) that the sidetrack well 98/11a-6Z has encountered the top of the Sherwood Sandstone reservoir below the level of the 98/11-3 oil water contact and did not penetrate the predicted fault bounding the target Colter Prospect. The well will now be plugged and abandoned and the rig released.
As previously reported on 25 February 2019, the Colter well (98/11a-6) was drilled as a vertical well with the Ensco-72 jack-up rig and reached a Total Depth of 1870m MD in the Sherwood Sandstone.
The well was drilled to appraise the 98/11-3 well, drilled in 1986 by British Gas, within the Colter Prospect. The 98/11a-6 well unexpectedly remained on the southern side of the Colter Prospect bounding fault but encountered oil and gas shows over a 9.4m interval at the top of the Sherwood Sandstone reservoir.
A petrophysical evaluation of the LWD data has calculated a net pay of 3m. Similar indications of oil and gas were encountered in the 98/11-1 well, drilled in 1983 by British Gas, within the Colter South fault terrace.
Provisional analysis of the new data indicates that the two wells may a share a common oil-water-contact having both intersected the down-dip margin of the Colter South Prospect. The Operator (Corallian Energy Limited) gave its most recent assessment of the Colter South Prospect prior to drilling the 98/11a-6 well at an estimated mean recoverable volume of 15 mmbbls. Further work will be required to refine this assessment with the new well data.
A decision was made by the Joint Venture to drill a side-track (98/11a-6Z) to the north to evaluate the Colter Prospect.
The well has now been drilled to a Total Depth of 1910m MD and encountered the Sherwood Sandstone below the oil-water-contact of the 98/11-3 well. Initial evaluation of the data from both wells indicates that the Colter Prospect is smaller than pre-drill estimates.
The Colter South discovery remains an opportunity to evaluate further as it is now really more extensive than indicated by the pre-drilling mapping. In addition, the side-track encountered oil and gas shows in the Jurassic Cornbrash-Lower Oxfordian interval, the producing reservoirs in the Kimmeridge oilfield, and this provides an interesting potential target on trend to the west within the onshore licences held by the Joint Venture.
The data from these well results and existing data will be incorporated to determine the best forward plan.
The Joint Venture partners would like to thank the well operator Fraser Well Management, rig operator Ensco and all the many contractors who assisted with the drilling operations which have been completed safely in an environmentally sensitive area.”
Malcolm Butler, Chairman and CEO of Baron, commented:
“While the drilling campaign indicates that the Colter Prospect is smaller than expected, it has demonstrated that the Colter South Prospect is larger than initially thought and has also given encouragement for our adjacent onshore prospects by encountering good shows in the Middle Jurassic. We will now integrate the results of drilling into the seismic data and evaluate the way forward to commercialisation of the Colter Prospect and the enlarged Colter South Prospect.”
Sachin Oza, Co-CEO of Reabold, commented:
“We were delighted to make an oil discovery with the Colter well, and with the sidetrack effectively giving us two wells worth of data, the operator is now in a position to undertake the necessary work to determine the optimum forward plan. This offsets the disappointment around the lack of commerciality within the northern Colter fault terrace.”
Stephen Williams, Co-CEO of Reabold, commented:
“Reabold continues to move through a highly active period of drilling, and we look forward to updating the market with the results from the first Monroe Swell well shortly, before moving ahead with additional drilling in California, at West Newton onshore UK and the Parta license in Romania.”
Simon Gorringe, CEO of Andalas Energy and Power PLC said: “The Colter appraisal programme has delivered a larger than expected Colter South prospect and significantly increased our understanding of the broader Colter prospect. The results of the sidetrack does, however, indicate that overall the Colter prospect is smaller than initially expected, but the results from the drilling of the sidetrack did deliver encouragement for our adjacent onshore prospects from the good shows encountered in the Middle Jurassic.
“The joint venture will now integrate the results of the programme into its evaluation of the way forward to commercialisation of the Colter prospect and the enlarged Colter South prospect. We have now met our financial obligations under the farm-in agreement and there are currently no outstanding obligations under the licence.”
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