CALVERT DEEP COTTON VALLEY SAND PROSPECT, ROBERTSON COUNTY, TEXAS, USA
Arbol Resources, Inc. (Arbol) is the operator of a 15,000-acre lease block located in northwestern Robertson County, near the community of Calvert, Texas.
The oil/gas leases were acquired beginning in mid 1997 through mid 1998. The majority of the oil/gas leases are Five (5) year paid up leases that begin expiring in June 2002. The lease block overlays a large graben in the Mexia-Talco Fault system.
Arbol conducted a proprietary 3D seismic survey in the summer and fall of 1998. The 3D processing and interpretation displayed several deep and shallow prospects. In the spring of 1999 Arbol drilled the Cristina #1 well (a Smackover Prospect). The Cristina #1 well location was strategically located to take advantage of specific geologic information from two (2) nearby wells.
1) In the mid-1980’s Houston Petroleum Company drilled the Pauline Burnitt #1 well (a vertical Georgetown/Buda Prospect). This well produced gas in the Buda formation and was shut-in due to the lack of a gas pipeline infrastructure. The well was shut-in until the summer of 2001. The Cristina #1 well offsets the Pauline Burnitt #1 well approximately 2000 ft to the southwest.
2) Magnolia Petroleum Corporation drilled the Hill-Anderson #1 well in the 1940’s. The well encountered 30’ of gas productive Cotton Valley Sand (CVS). The well was electric logged with old induction tools without any significant reservoir quality information obtained.
The Cristina #1 well offsets the Hill-Anderson #1 well approximately 4000 ft to the south.
Original seismic interpretation by Arbol’s consultants indicated the Cristina #1 would encounter the CVS significantly higher to the Hill-Anderson #1 well. Unfortunately, the Cristina #1 well encountered the CVS approximately 400 ft low to the Hill-Anderson #1 well.
Nevertheless, the CVS appeared gas productive according to both the electric and mud logs. Arbol fractured and production tested the CVS, with water production and approximately 50-100 mcfd of low BTU natural gas.
Arbol abandoned the CVS, attempted a non-completion in the Travis Peak formation and prepared to drill opposite short radius laterals in the Buda formation. This project was completed in early 2000.
The 3D seismic survey was reprocessed and reinterpreted in early 2001. Utilizing the geologic, reservoir, and velocity data collected in the Cristina #1 well, a CVS Prospect extending from the Cristina #1 well up to the Hill-Anderson #1 well was confirmed. The CVS is trapped against one of the main graben faults and demonstrates closure in all remaining directions. A powerpoint presentation is available upon request.