Bakken Oil Formation

Presented by

Century Energy LTD.

Century Energy LTD.• Century Energy Ltd (TSX.V:CEY, PK:CEYFF) is a junior oil and gas

exploration company actively pursuing resource opportunities in North America. The company holds five leases adjacent to the Roncott / Bakken Oil Field, which is prospective for both horizontal and vertical drilling. Century Energy Ltd. has signed a farm-out agreement with TriAxon Resources Ltd. of Calgary for the drilling of a horizontal well before December 31st, 2008, on Century's acreage adjacent to the Roncott/Bakken oil field in southeast Saskatchewan.

• Please visit www.centuryenergyltd.com for more information.

Bakken Geology

Bakken Formation is comprised of 3 MembersUpper Shale Member– Source & Seal

Middle “Siltstone” Member– Reservoir & Migration Conduit

Lower Shale Member- Source & Seal

-Middle Member Depositional Environment=Complex

Marginal Marine to Marine Shelf Environment with a

variety of rock types ranging from shales to siltstones

and fine grained sandstones, lime- and dolostones.

(Described as a ‘carbonate/clastic tug of war’ by Hess)

James A. Peterson, University of Montana

Bakken Comparison – Canada / USA

- The Bakken zone is geologically and lithologically complex across the Williston Basin with numerous marginal marine depositional environments and resultant rock types

- Montana rock types represent carbonate bank deposits

- North Dakota, Saskatchewan, and Manitoba rock types represent a variety of marginal marine deposits

- The zone is about 10,000 feet deep in Montana and North Dakota, about 5,000 feet in Viewfield Saskatchewan and about 3,000 feet in Sinclair Manitoba

- OOIP per section for the different areas is estimated to be in the order of 3 MMStb to 7 MMStb

- The oil is light, at about 40 – 45 degrees API

- Permeabilities are in the order of 0.001 to 1 millidarcy

- The fractured Bakken in North Dakota has initial rates of over 1,000 Bopd, the Montana Elm Coulee wells produce initially about 500 Bopd, the Viewfield wells commence at about 200 Bopd and the Sinclair vertical wells start producing at rates of about 50 Bopd

- The deeper areas have lesser well density; about 2 Hz wells per section, or less, as compared to Viewfield with 4 Hz wells per section and Sinclair with 16 vertical wells per section

- Current Bakken production rates are estimated to be 130,000 Bopd from 650 wells in Montana, 70,000 Bopd from 400 wells in North Dakota, 40,000 Bopd from 550 wells in Viewfield and 10,000 Bopd from 725 vertical wells in Sinclair

Viewfield BakkenReserve Estimation Methods

- Volumetrics: Volumetric estimates using vertical well open hole logs, samples and core control

- Computer simulation work on the Bakken to assist in estimating solution gas drive recovery factors, potential interference effects between wells and the expected production profile

- Type curve analysis

Viewfield BakkenReserve Estimates

• - OOIP: 4 MMstb per section developed with 4 Hz wells per section; 1 MMstb OOIP per well

- Recovery Factor of 10%, 100,000 barrels of oil per well. 2P at 12.5%, 125,000 barrels of oil per well, and 3P at 17.5%, 175,000 barrels of oil per well.

- This represents the “average” well that has been used as an analogue. Reserves assigned to both drilled wells and offsetting locations will be dependent upon actual production characteristics of producing wells in the vicinity

Reserves Evaluation Issues

- Extremely active, over 100 wells per month, public and confidential data

- A multitude of undrilled reserves, resource and prospective locations

- Short life performance history on the steep decline portion only; long life lesser decline only a guess

Reserves Evaluation Issues

- All wells are not “type” wells, sand is not a blanket (sink holes, crater features, areas of anomalous tighter or sandier sediments and structural components)

- All horizontal wells do not keep perfectly within the sand at an optimum position, nor do all fracture stimulations stay “in the zone”

- Even “Packers Plus” fracture methods are not the same due to different number of intervals and fluid type sensitivities

Bakken Booking Methodology

- Until the advent of horizontal drilling and focused fracturing techniques, the Bakken oil play was limited to stimulated vertical wells in areas where the average permeability was in the order of 10’s of millidarcies. Any other Bakken oil areas with low permeability were uneconomic to develop even though producible oil was established.

- The prospective resources in the Bakken play, both in the USA and Canada, could be very large. In April 2008, the United States Geological Survey assessed the mean undiscovered volume of oil in the Bakken in the Williston Basin area of Montana and North Dakota, combined, to be 3,650 MMstb.

- Resources and reserves bookings in the Bakken will be done by analogy using type curves. The play lends itself to a statistical approach, taking into account available geological and production information.

- Prospective resources will be rapidly upgraded to contingent resources or, more likely, to reserves, as wells are drilled.. The USGS considers the Bakken oil play to be largely a resource play

- Resource and reserves assignments will be dependent on geological and well control. A single successful oil well can result in a number of offset reserve and resource locations. A few strategically placed successful wells in an area can result in the booking of multiples of a single well’s offset location potential.

Bakken Booking Methodology