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. This transaction was completed in August 2021 ahead of the drilling.

In October 2021 - PRM drilled the first Bowsprit-1 well to appraise the upside potential of the project. The well was drilled to test an up dip sand/ potential extension to the main project area. The up-dip sand was dependent on a fault seal to contain the prospective oil.  Unfortunately, the well once drilled showed that the sand only contained residual oil, indicating that the fault does not seal.  The well was suspended at a depth of 3,000ft for future re-entry.

The forward plan is to use the data gathered from the vertical well to refine the mapping and understanding of the proven Upper Miocene Sand that flowed oil and the 1960’s (T1) with a view to side-tracking the Bowsprit-1 well and drilling a horizontal production well into the T1.  

Details of the Louisiana Oil Leases

Prominence holds and operates the Bowsprit Petroleum Lease at 100% working interest, covering a total of 635 acres in the Breton Sound Area of Louisiana.

The Lease is 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 Lease is 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.

Reserves Attributed to Bowsprit-1

The field consists of a proven Upper Miocene Reservoir (T1) at a depth of approximately 7,400ft TDSS

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

Resource Classification

Confidence Level

Net Reserves

Net Reserves

Net Cash Flow (NPV0)







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

[1] See Release of 21 July 2022 for full report.

[2] 0.69 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 30ft 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 the Bowsprit T1 reserves can be developed with a single horizontal well and could potentially be produced via tie-back to a nearby production facility.

Saratoga Resources drilled and produced two 750ft horizontal wells in an analogous quality, pressure depleted sand, 12km south of Bowsprit, one of which tested at over 1,500 bopd.   

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

  1. Appraise the full field potential by
    • Test 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 for full field development planning and implementation.
  4. Suspend the well for future side-track and horizontal development drilling of T1.

Forward Plan

PRM drilled the vertical part of the Bowsprit well to appraise the project upside in October 2021. The well was drilled to a depth of approximately 8,200ft. The main target was 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.  Unfortunately, the T2 reservoir only contained residual oil saturation and does not contain producible oil. 

After appraising the field to a depth of 8,200ft, the well was 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 in the northern hemisphere spring/summer. During the suspension, the data gathered will also be used for selection and permitting of an appropriate pipeline and sizing of wellhead facilities and 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 pre vertical well data, the horizontal well is independently estimated to have 2P reserves of 330,000bbls.  This estimate will be updated once the vertical well data is incorporated into the data set.

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