Bowsprit Oil Project

On the 14 August 2017, The Board of Prominence Energy Ltd (“Prominence” or “the Company”) announced that the Company and Pinnacle Exploration Pte Ltd (“Pinnacle”) secured a new oil project through bidding on open acreage in the inland waters of the State of Louisiana, USA.  The parties named the field “Bowsprit”.

On 29 July 2019 Prominence announced the Company has agreed to acquire Pinnacles 50% interest in the project and move to 100% working interest.  

In August 2021 - PRM will be drilling the First Bowsprit well to appraise the upside potential of the project.  

Details of the Louisiana Oil Leases

Following the completion of the buyout, Prominence will hold and operate both Bowsprit Petroleum Leases at 100% working interest, covering a total of 1,154 acres in the Breton Sound Area of Louisiana.

The Leases are located approximately 70km southeast of New Orleans in approximately 3 meters of water.  There are 14 historical wells, drilled between 1952 and 1982, within the Leases and extensive existing 2D and 3D seismic over the Leases.  The Leases are near the boundary of St Bernard and Plaquemines Parishes that covers the transition zone from onshore to the federal waters offshore Louisiana.  The region is a prolific hydrocarbon province, the majority of exploration and production occurred in the 1960’s and 1970’s and it is estimated that the two Parishes have produced over 1.2 billion barrels of oil and 5.2 trillion scf of gas.

Field Potential

Prominence has conducted extensive internal work assessing the Bowsprit project, based on public domain and purchased data. Prominence has had three independent consultants review the project and verify its potential. 

Reserves Attributed to Bowsprit-1

The field consists of a proven Upper Miocene Reservoir (T1) at a depth of approximately 7,400ft TDSS overlying a secondary ”Prospective” target Middle Miocene Reservoir (T2).

Reserves estimated by Netherland, Sewell & Associates, Inc. (NSAI) on the Bowsprit Project. [1] 

Resource Classification

Confidence Level

Net Reserves

CAPEX for Development

Net Cash Flow (NPV0)






US$ million

US$ Million

US$ Million

A$ million[2]

Undeveloped Reserves (T1)


1P (90%)






2P (50%)






3P (10%)






Table 1 – Bowsprit Field Upper Miocene Reservoir T1 Reserves

Resource Classification

Confidence Level

Prospective Net Resources Mbbls


Prospective Resources (T2)

1U   Low Case


NSAI estimate the Geological chance of finding and producing commercially significant hydrocarbons from the T2 reservoir as 25%. The Principal risk is whether the fault to the north-west of the field is sealing.

2U  Best Case


3U  High Case


Table 2 – Bowsprit Field Middle Miocene Reservoir (T2) Prospective Resources

Cautionary Statement – Prospective Resources are the estimated quantities of petroleum that may potentially be recovered by the application of a future development project(s) related to undiscovered accumulations. These estimates have both an associated risk of discovery and a risk of development. Further exploration appraisal and evaluation is required to determine the existence of a significant quantity of potentially moveable hydrocarbons.  See full Cautionary Statement and full resource definitions in the ASX release on 5 February 2020.

[1] See Release of 5 February 2020 for full report.

[2] 0.75 USD per AUD


Bowsprit is assessed to contain an undeveloped conventional Miocene aged oil sand at a depth of approximately 7,400ft (2,255m) that is located above a deeper 9,500ft deep gas and condensate field that was developed in 1960s by Shell and produced through to early 1990s.  Consequently, the Bowsprit field contains 14 vertical well penetrations and has demonstrated producible oil.  One 20 to 50ft thick oil sand was flowed successfully from four vertical wells and produced approximately 75,000 bbls of oil and approximately 1 Bscf of gas was produced from an overlying sand at 7,200 ft.  Limited to vertical well technology of the day, full field development was not commercially practical at the time (initial well production rates of ~100 bopd declining to ~40 bopd).  The whole area was relinquished by the former owners in the 1990s prior to the advent of horizontal drilling.

Prominence has determined that following confirmation of the resources with the appraisal well, the Bowsprit structure can be developed with up to five horizontal wells and could potentially be produced through a simple unmanned production platform or via tie-back to a nearby production facility.

Saratoga Resources drilled and produced two 750ft horizontal wells in an analogous quality, albeit thinner and pressure depleted sand, 12km south of Bowsprit, one of which tested at over 1,500 bopd.  Prominence anticipates drilling Bowsprit wells with longer horizontal sections, in virgin pressure sand with a thicker column of oil, that should, therefore, meet or exceed the performance of the Saratoga wells. 

Prominence has conducted 3D geological modelling of the Bowsprit Field in order to select an optimum first well location.  A primary well location has been selected and permitting of the first well has been completed. The objectives of the first well are:

  1. Prove the field reserves by
    • Test/Prove the Prospective Resources in the “undrilled” portion of the field with the vertical pilot well
  2. Data gathering of seismic velocity data and rock attributes for quantitative seismic interpretation, and
  3. Detailed reservoir parameters and oil properties for full field development planning and implementation.

Forward Plan

PRM is planning to drill the vertical part of the Bowsprit well to appraise the project upside in August 2021 with the exact timing subject to the rig schedule with other jobs. The well will be drilled to a depth of approximately 8,600ft. The main target is the T2 Middle Miocene Sand (see Figure 1 below) that sits under the proven field and runs up dip approximately 100ft above the known oil to a potential fault closure.  If this T2 reservoir is proven to contain oil the 2U/3U Prospective (recoverable) Resources are estimated as 1.8 – 4.1MMbbls. The independent auditor estimates the chance of success at 25%.

After appraising the field to a depth of 8,600ft, the well will be suspended at a depth of approximately 3,000ft for future re-entry.  The intention is to use the data gathered from the vertical well to optimally plan for the drilling of the horizontal production section of the well into the previously produced Upper Miocene T1 reservoir after hurricane season. During the suspension, the data gathered will also be used for selection and permitting of an appropriate pipeline and sizing of wellhead production facilities and/or tie in capacity negotiations. Upon re-entry of the well, the horizontal section will be drilled into the proven previously produced (T1) upper Miocene reservoir part of the field.  Based on the current data, the horizontal well is independently estimated to have 2P reserves of 330,000bbls.  

 Cross Section

Figure 1 - North West to South East cross-section through Bowsprit Field.