Ledeuix Exploration Permit, France – not using

Horizon holds a 100% interest in the Permit, which is located in the Aquitaine Basin of south-western France. The basin contains the largest natural gas fields in France: Lacq and Meillon, which combined have produced 11 TCF of gas to date. Hydrocarbons were sourced from the Lower Jurassic aged shales and marls, and have migrated into Jurassic and Cretaceous aged naturally fractured carbonate reservoirs contained in folded thrust sheets of the Pyrenean fold belt.

Eleven wells have been drilled in the Permit, with two of those wells testing hydrocarbons. Saucede-1 drilled in 1978 by Esso was a gas discovery flowing an average 9 MMscf/d over 19 days. It was placed on production 1981- 1985 and again in 1988 to 1993. The well produced a cumulative 1.85 BCF of gas from Lower Cretaceous and Jurassic aged naturally fractured carbonate reservoirs between 4,200 and 5,410 meters below sea level. Reservoir engineering analysis has indicated significant wellbore damage, caused by overweight drilling fluids and poor completion practices which could have resulted in poor well performance.

A number of leads have also been identified in different thrust sheets that have similar characteristics to the Saucede gas discovery at shallower depths that provide significant upside potential.

Map of Acquitaine basin existing pools

  • The Ledeuix permit is positioned in the North Pyrenean fold and thrust belt
  • The cross-section shows the subsurface structuring associated with the Pyrenean Oregeny and the location of the Ledeuix permit
  • The map to the right shows the regional structures in the South Acquitaine basin and the location of known hydrocarbon accumulations
  • The two largest gas accumulations in France sit just north and east of the permit
  • Seven prospective structures have been identified on the permit and are shown in the map below
  • These structures are individual thrust sheets which have been mapped by Petromanas over the permit
  • UPIIP best estimate of individual structures range from 41 Bcf up to 259 Bcf

Saucede Gas Discovery:

  • Drilled 1979 by ESSO with TD at 5,638 m
  • Difficult drilling condition compounded by inadequate blow out preventer leading to poor casing design
  • Tested gas from Jurassic aged naturally fractured carbonate reservoirs between 4,200 – 5,500m
  • Heavy drilling fluids to control high formation pressure above reservoir zones may have caused significant formation damage

Well Test & Production Summary

  • Flow rates averaged 21 MMscf/d during test
  • Well placed on production 08/1981 to 06/1985 with production rate 1.45MMscf/d declining to 0.46 MMscf/d
  • Cumulative production of 2 bcf
  • Esso test analysis concluded well was underperforming due to possible formation damage and poor completion practice:
  • Inadequate perforation density (one shot/ft.) and small gun size
  • Inappropriate acid strength leading to possible precipitation in reservoir casing possible blockage
  • Insufficient diversion for acid job resulting in only one zone being stimulated
  • Esso concluded that the zones were not fully evaluated


  • Independent NI51-101report assigned 720 bcf contingent resources to the Saucede structure
  • Upside potential in higher thrust sheets and structures in same naturally fractured reservoir