Rose Petroleum plc

Positive Mancos Shale Core Results


Rose is pleased to provide a positive update on the core analysis results from the State 1-34 well taken within the Mancos Shale interval in the Uinta Basin

Rose Petroleum plc, the AIM-listed (AIM: ROSE) natural resources company, is pleased to provide a positive update on the core analysis results from the State 1-34 well taken within the Mancos Shale interval in the Uinta Basin acreage in Utah.


  • Mancos core analysis results correlate strongly or exceed parameters used by Ryder Scott to calculate the Prospective Recoverable Resources of 709MMbbls oil and 4.26 TCF gas
  • Results provide increased confidence in horizontal well locations following extensive analysis
  • Permitting process for six new Mancos wells on-going
  • First horizontal well to target the Mancos Emery formation, the reservoir or "carrier" bed - anticipate spudding of first well before YE2015
    • Locating in the Cisco Dome field will offer cost reductions due to existing infrastructure and gathering system for gas sales
    • Mancos benefits from a low breakeven price

Matthew Idiens, Group CEO, commented:

"Following extensive analysis of these extremely encouraging core results we are feeling ever more confident of the prospectivity of the Mancos Shale. Most importantly, overall the results match or exceed the key assumptions and estimates used by Ryder Scott in their resource calculations, thus giving further credence to their significant prospective recoverable resource numbers for the Mancos of 709MMbo and 4.26 TCF gas.

"We are now in a position to confidently define our first horizontal well location and with the permitting process underway we are excited about the months ahead as we anticipate spudding our first Mancos Shale well before the year end."

Further information

The State 1-34 well was drilled to a total depth of 3,200ft. The core samples were taken from various locations, mainly targeting the Mancos shale interval which begins with surface exposure and extends to a depth of approximately 1,180 ft in this area. The additional depth drilled beyond the base of the Mancos was only to test the conventional target (Dakota to Entrada) identified below from 2-D seismic data and confirmed through rotary core samples but, as previously announced, was breached with water when completion was attempted. However, within the upper levels of the Mancos away from the conventional targets and within the Mancos shale, two whole cores intervals of 60' and 45' were taken at depths of 570-630' and 720-780'. 37 Mancos rotary core samples were recovered with 13 in the conventional section.

Core results matched or surpassed Ryder Scott's parameters for the Mancos Shale resource calculation of 709MMbo and 4.26 TCF gas for key criteria:

  • TOC ("Total Organic Content") used by Ryder Scott were 1.5 to 2% the State 1-34 has an average background of 1.5 to 2 % with a 150' "kitchen" interval in the Ferron member of TOC over 2.75% and up to 4.5%
  • Potential target reservoir or "carrier" beds identified in the same four Ryder Scott defined Mancos intervals with porosities in the 6-9% range
  • State 1-34 average porosities 0.5-1% higher than Ryder Scott study (P50 values)
  • State 1-34 hydrocarbon (oil) saturations both in core and in situ are in line with the Ryder Scott study
  • Net potential "carrier" beds to Gross ratios are comparable with Ryder Scott
  • Tmax (Thermal maturity) confirms that the State 1-34 is within the "Intensive Generation Expulsion" window for the Ferron member

Halliburton ran traditional open-hole, dipole sonic and formation imager logs. Weatherford provided their Well-Site Geological Services including mud logs and its Shale Resource Analysis ("SRA") with 10' samples. In addition to this, three different types of core samples were taken by Weatherford: whole core barrels (with plugs), rotary cores, and chip samples of the end of each 3 ft whole core. All of these samples were subjected to the same battery of core analysis testing to calibrate results. TOC, S1 and S2 results all calibrate between the sample points. This provides Rose with confidence on the accuracy of the results.

TOC is the weight percentage of Total Organic Content, S1 represents the volatile hydrocarbon content (moveable) in a sample (mg/g), and S2 is the amount remaining hydrocarbon generative potential and provides the quantity of hydrocarbons that the rock has the potential to produce through continued heat and temperature.

In addition, the Tmax (Thermal maturity) shows the 150ft thick high TOC "kitchen" interval in the Ferron formation within the Mancos has kerogen type that has been "cooked" sufficiently over time to be in the oil window. Directly above the Ferron interval lies a known producing 50ft porous "carrier bed" or reservoir interval, the Mancos Emery formation which is where the Company expects the oil generated in the Ferron to migrate to and will be its initial target formation for a horizontal well. The analysis also shows open fractures within the cores consistent with the fractures identified in the Halliburton Image/Dipole logs, which were also run, and confirmed the fracture azimuth to be Northwest to Southeast.

With the basin dipping North and the fractures running NW/SE, the orientation of the horizontal well location may now be selected with more confidence. Since permitting the State 1-34 well location, we have acquired the Cisco Dome acreage in a deeper part of the basin and will use existing infrastructure which should offer additional cost reductions and potential to fast track tying into a gathering system for gas sales.

Ty Watson (B.S. Petroleum Engineering), President of Oil & Gas for Rose Petroleum plc, who meets the criteria of a qualified person under the AIM Rules - Note for Mining and Oil & Gas Companies, has reviewed and approved the technical information contained within this announcement.