Nighthawk Energy plc has announced details of well test results and development plans in respect of the Jolly Ranch Group project (Jolly Ranch, Middle Mist and Mustang Creek).
Jolly Ranch Development Update
The Jolly Ranch project is located in Lincoln, Elbert and Washington Counties, Colorado. Nighthawk holds a 50% working interest in the Jolly Ranch project, and Running Foxes Petroleum Inc. ("Running Foxes"), the Operator, holds the remaining interest.
The primary target of the initial drilling program was the regional Marmaton formation which has been present in each of the wells drilled. Secondary targets were the Atoka and Cherokee shales from which BHP, Mull and Anschutz produced oil within the Denver Basin on a commercial basis during the 1980s and 1990s prior to relinquishing the acreage due to low oil prices.
To date, of the shale zones only the Lower Atoka shales have been evaluated by the Company and they have delivered results that have greatly exceeded expectations. The Upper Atoka shales and Cherokee formation also contain hydrocarbons and await testing.
The Atoka and Cherokee shales can be compared geologically to the prolific Bakken shales, which the United States Geological Survey estimated in April 2008 to contain a technically recoverable oil resource of between 3.0 and 4.3 billion barrels. Shale plays such as the Barnett, Marcellus, Fayetteville and Bakken, have become the most active hydrocarbon exploration and development targets onshore US in recent years. Regional studies indicate that the Atoka and Cherokee shales are continuous throughout the whole Jolly Ranch Group project area and can now be considered a new regional shale play.
In addition, hydrocarbons were observed in both sample and log shows in respect of the Codell formation of Cretaceous age from 3,000 to 3,500 feet in the Jolly 2-1 and Jolly 16-1. Subsequently, a further four wells have been staked adjacent to the Jolly 16-1 to test this zone. The Operator plans to secure a smaller drilling rig to drill and complete this shallower zone.
To date, five wells have been drilled to target depth, all of which encountered hydrocarbons in multiple formations. Planned wells are projected to be vertical to minimise costs. The current status of these wells is as follows:
The Craig 8-1 well has been perforated, acidized and fracced in the Lower Atoka shales from 6,736 to 6,850 feet. The well was acidised and small amounts of oil and gas and acid were swabbed back. The well was stimulated with a slickwater frac of 4,000 barrels of KCL water and 37,000 lbs of sand. The well flowed back frac fluid and increasing amounts of oil and gas. Swabbing of the well indicated equivalent daily rates of over 300 BOPD. Fluid levels during swabbing did not fall below 4,000 feet from surface indicating excellent hydrocarbon inflow.
Under production test the operator limited production to 80 BOPD to minimise frac sand movement into the well. Sand re-entry into the well bore, which is a common occurrence in shale plays, will disappear after a short period and does not affect the ultimate recovery of oil from the well. Following completion of the initial evaluation, a higher capacity pump jack will be installed.
The Jolly 2-1 well was completed in the Marmaton reservoir from 6,841 to 6,852 feet. The well is currently producing 25 BOPD and the oil cut is increasing as the well is cleaned up. The oil is sweet, 36 degrees API gravity. A higher capacity pump jack to increase oil production further will be installed. The Marmaton reservoir is present in all the wells drilled by the Company on the project as well as the previous wells drilled by other Operators.
The Jolly 16-1 well has been perforated in the Lower Atoka shales from 7,236 to 7,380 feet, acidized and swabbed. The well was initially acidised and flowed back small amounts of oil and gas and acid water. The Lower Atoka Shales were then stimulated with a slickwater frac using 5,000 barrels of KCL water and 50,000 lbs of sand. The well immediately flowed back frac water and significant oil and gas. Shut-in pressures during the flowback exceeded 1,000 psi at surface. The well flowed 76 barrels of oil (excluding frac water) over a 17 hour period. The oil and gas cut increased throughout this production test. Fluid levels during swabbing did not fall below 4,000 feet from surface. The well is currently shut-in whilst a pump jack and associated surface equipment are installed. Production is expected to begin within the next 10 days.
Fracture analysis of specialty logs by Fronterra Geosciences indicates numerous natural fractures in the shales present both in the Craig 8-1 and the Jolly Ranch 2-1 wells, which benefits the productivity of the reservoir. The Jolly 16-1 is seven miles to the northwest of the Craig 8-1 indicating a large and continuous reservoir.
The Jolly 4-13 has been drilled to the Arbuckle formation and cased to a total depth of 8,307 feet. The well has similar Marmaton, Cherokee and Atoka formations to the Craig 8-1, Jolly 2-1 and Jolly 16-1. The well has been logged through casing for further evaluation. The operator plans to complete the well in the Lower Atoka shales. The Jolly 4-13 is five miles to the north of the Jolly 16-1.
The Craig 4-4 has been drilled to the Arbuckle formation and cased to 7,653 feet. The well has similar Marmaton, Cherokee and Atoka formations as the Craig 8-1, Jolly 2-1, Jolly 16-1 and the Craig 4-4 wells. The operator plans to begin completion of the Lower Atoka shales within 14 days. The well is four miles to the west of the Craig 8-1 and six miles to the south of Jolly 16-1.
The Craig 15-32, the sixth well overall and the third in the current 10 well program, spudded on September 22, 2008. The well will shortly reach total depth and the Operator plans to complete the well in the Cherokee shales.
The Jolly Ranch Group project represents a high quality shale play as it is producing primarily oil. The Operator plans to drill the wells targeting the shale zones initially on 80 acre spacing, providing over 2,800 locations. Wells targeting the Marmaton formation will be drilled separately on 40 acre spacing.
The three shale wells drilled by BHP, Mull and Anschutz in the 1980s and early 1990s were acidized only with 500 to 4,000 gallons of HCL. The wells were not stimulated by fraccing and produced an average of 18,000 barrels per well prior to the operators plugging the wells due to low oil prices. These wells only drained oil from the reservoirs within a few feet of the wellbore as acid is non-invasive. Present fraccing technology which was not available at that time is now applied to all shale plays to maximise production and create conductivity in the reservoir.
Typically, stimulation by fraccing increases recoverable reserves from shale reservoirs by three to ten times. Both the Craig 8-1 and Jolly 16-1 wells were acidized in the same way as the previous three shale wells and made limited amounts of oil and gas. After fraccing, indicated flow rates are now exceeding 300 BOPD with excellent reservoir conductivity.
An initial evaluation by consulting engineers, Apex, indicates the frac length to be 200 to 400 feet exposing much more of the reservoir to the wellbore. Based on the initial results from the Craig 8-1 and Jolly 16-1, the operator is expecting to increase the response from the reservoirs significantly.
The Jolly Ranch Group project now has 13 further wells permitted, which are planned to be drilled before the end of the year. In addition, the Operator is in the process of staking ten wells in the Middle Mist area and an additional 20 wells at Jolly Ranch.
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