Coastal Energy Suspends Wells at Phu Horm

Coastal Energy said that drilling and testing of two development wells, PH-6 and PH-7, on the Phu Horm gas field onshore Thailand has been completed, with both wells being suspended. PH-6 and PH-7 were directionally drilled from the PH-4 production well location and were expected to be completed as support wells.

The PH-6 well was drilled to a total depth of 2,468 meters sub-sea and encountered the primary reservoir, the Pha Nok Khao ('PNK'), at 1,864 meters sub-sea. The well was drilled under-balanced through the main reservoir section and flowed up to 3 million cubic feet of gas per day ('mmcfd') while drilling and flow tested at a rate of 1.1 mmcfd. Although the reservoir is gas-bearing, further evaluation is required in order to confirm the reason for the low flow rates--which could be due to formation damage while drilling or low porosity and permeability. The forward program for PH-6 is currently being discussed by the field partners.

The PH-7 well encountered the PNK reservoir at 2,024 meters sub-sea, approximately 105 meters lower than anticipated. Preliminary evaluation of the well suggests the reservoir was tight with very low porosity and permeability.


Testing of the Cobble Cuesta 1-12 exploratory well, which was originally drilled and suspended in October 2006, was completed with no hydrocarbons being recovered.

Three tests were carried out over a number of zones between 946 meters - 1,464 meters and recovered drilling fluid. The well has been plugged and abandoned.

Frank Inouye, Chief Executive of Coastal, commented: "We are obviously disappointed with the drilling results on the Phu Horm gas field, however the two wells have confirmed the fact that the geology of the field is more complicated than originally envisaged. Fractured carbonate reservoirs by nature are very complicated, and our exploitation of additional reserves from Phu Horm will require a better understanding of the field's geology. Although it is premature to discuss the effect these wells will have on the field's overall reserves, we must not forget the fact that Phu Horm continues to produce in excess of 90 mmcfd from the PH-3, PH-4 and PH-5 wells and that the PH-6 well did not encounter any formation water through the reservoir zone."

Coastal Energy is an oil and gas exploration, development, and production company, with core assets onshore and offshore Thailand and Nevada, USA.