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IEV strikes oil and gas onshore West Java in Indonesia

13th March 2015

IEV Holdings has announced that hydrocarbon bearing intervals have been identified in the Parigi and Upper Cibulakan Formations in the CLS-1TW development well in Cilamaya Structure, onshore West Java

IEV Holdings has announced that hydrocarbon bearing intervals have been identified in the Parigi and Upper Cibulakan Formations in the CLS-1TW development well in Cilamaya Structure, onshore West Java
The well encountered gas shows within the Parigi Formation over a gross interval of approximately 470 mMD. Source: IEV Holdings

The CLS-1TW is a replacement well of the CLS-1 well drilled in 1980.

The CLS-1TW well has been successfully drilled to Total Depth of 2,117 metres measured depth (mMD).

Hydrocarbon bearing intervals have been identified based on results from mud logs during drilling and a preliminary interpretation of a full suite of electric wireline logs. Several depth intervals have been identified for production testing.

The well encountered gas shows within the Parigi Formation over a gross interval of approximately 470 mMD.

This is the first occasion that the Parigi Formation has confirmed good gas responses in the Cilamaya Structure.

Potential gas bearing pay zones were noted from 976.0-978.0 and 980.5-981.5 mMD. Other notable potential gas intervals were at 1023.5-1029.5, 1015-1054, 1091.5-1095.5, 1375.5-1376.5, and 1380.0- 1381.0 mMD and could be either matrix or fracture intervals.

Many of these intervals showed high total gas unit counts and high methane readings during chromatography of mud returns. Further, the electric wireline logs demonstrated density-neutron crossovers, interpreted as indications of gas bearing intervals.

The well recorded oil shows in the Upper Cibulakan Formation from cuttings returns over an approximate 213 mMD gross interval. Dull, pale brown, even fluorescence was found in limestone and minor fine grained sandstone intervals.

Fluorescence, as an indicator for the presence of hydrocarbons, increased with depth from approximately 10 per cent at the top of the unit to 90 per cent at the base of unit.

Potential oil bearing pay zones in the Upper Cibulakan formation are at 1,778.0-1,779.0, 1,955.0-1,961.0, and 1,988.0-1,991.0 mMD. Other potential oil intervals are at 1786.0-1787.5, 1800.0-1803.0 mMD.

Many of the above intervals showed high resistivity and good density-neutron character on electric wireline logs, which is a further indirect indicator of the presence of oil.

The electric wireline logs were run to a total depth of 2,117 mMD. The log suite comprised spontaneous potential (SP), gamma ray, caliper, density, neutron, photo electric factor (PEF), and resistivity. Only selected zones will be production tested due to the limitation in available perforating explosives as the well was originally planned for only two intervals. The production testing will involve flow testing and pressure build-ups to determine reservoir flow capacity and well deliverability, leading to updates in the quantification of reserves and resources in the Cilamaya and neighbouring Pabuaran structures.

Barring any unforeseen circumstances, test results will be announced as soon as the production testing program is completed, which is expected to be within the next 30 days.

Barring any unforeseen circumstances, following the completion of the production testing, IEV plans to commence production of the crude oil from CLS-1TW Z16 Upper Cibulakan Formation intervals, which will be delivered to the sale point at the Pertamina Refinery in Cirebon.

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