Bellevue #1 oil and gas well reaches top of potential pay zone at 850ft
  by: OilOnline
  Friday, October 03, 2008

Empire Energy Corporation International announced that Spauldings completed an 8.5in (216mm) pilot hole to a depth of 850ft (268m).  A 20in conductor will be established at the top of the hole to a depth of approximately 20ft or to where the rock becomes competent. The hole is now being enlarged to 17.5in (470mm) using the pilot hole to guide the larger 17.5in (470mm) air hammer drill bit to a depth of 830ft (260m). Stopping before the bottom of the pilot hole will allow the casing shoe to be set within the dolerite and should assure good pressure testing for the hole. Hunt Rig #3 should be able to safely proceed to drill a 13.5 in open hole into the expected potential pay zone after the casing has been cemented and the blow out preventer has been secured at the well head.

In the first top hole drilled, from surface to about 640ft (200m), the sequence consisted of hard basalt lava flows, with soft and unconsolidated porous inter-bedded river wash and volcanic ash. This hard and soft sequence created problems in drilling the hole, forcing Spauldings to cement up the hole several times to prevent water inflow, cavitation caused by water and to keep the hole stabilised so as to stop it from caving in. The second top hole was drilled adjacent to the first hole and took advantage of the inflow of cement grout from the first hole. The second hole encountered hard dolerite to 830ft (260m), then fractured and veined material and bottomed in probable silicified sediments (possible contact metamorphics) at 854ft (268m).

We expect to encounter a 960ft (300m) thick sequence of Triassic age (205 to 251 million year old) freshwater sandstones containing coal measures. The coal measures are expected to be intersected within the Triassic sequence, which we believe we are now in, between about 268 meters to 368 meters, and it is planned that these will be tested when the conventional Hunt #3 Rig is moved over the hole next week to commence drilling ahead to the total depth. It is planned that any coals drilled will be cavitated and fractured to enhance the anticipated coal bed methane gas recovery and flow tests will be undertaken to establish the potential commercial viability of any gas recovery from the formation.

Beneath the Triassic we expect about 510ft (160m) of Permian Ferntree Formation, a silt and clay marginal marine seal rock. The Hunt #3 rig will then drill on to intersect the Permian freshwater to deltaic Liffey Group, which includes the freshwater algal oil shale named Pelionite, within a sequence of sands and coals inter-bedded with carbonaceous siltstones. The organic rich shales of the Quamby Formation, which include the Tasmanite Oil Shale, are expected between 3,247ft (990m) and 6,527ft (1,990m) and will be flow tested for possible shale oil and gas. We will then drill on to the next pre-Permian target, a large bright spot on the sections, expected to be in the Gordon Group limestones. Because of the thinner than expected section of dolerite in the top hole, the depth to this bright spot target is now expected to be 8,528ft (2,600m) rather than the previously estimated 9,200ft (2,800m).

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