Hutch Jobe¹, Sid Bjorlie¹, Mark Petrichuk¹

(1) Burlington Resources, Farmington, NM

ABSTRACT: An Integrated Analysis of the Madison Formation: Madden Field, Fremont County, Wyoming

The ultra deep and ultra expensive drilling occurring in the Madden field of the Wind River basin commands a lot of preparation and analysis. This 25,000' foot reservoir possesses multiple trillion cubic feet (TCF) capabilities from no less than 4 wellbores to as many as 16. Daily production rates per wellbore range from 40 to 50 MMCF. These rates are constrained due to processing capacity. Wells are capable of substantially higher rates since calculated AOF's of more than 150 MMCF have been recorded.

The gas being produced is extremely sour and dirty. The H2S content hovers around 12% and is coupled with a CO2 content of 21%. This leaves a hydrocarbon content of only 67%, which is basically all methane. Expensive gas plant facilities are required to treat and process this gas. The current daily inlet volume is 130 MMCF but construction is underway to increase this to 310 MMCF at a cost of about 1.5 MM$ per million cubic foot.

The productive reservoir is a fractured dolomitized limestone situated on an immense structural closure. The structure closure is bounded on all sides via thrust faults with vertical displacements as high as 5000'. A gas column approximately 1200' thick has been proven and could increase to 1800' if the current drill well encounters a reservoir which is full to base. Ultimately the gas column could approach 3000' in thickness.

The justification of this project has been achieved through thorough investigation of the geology, geophysics, and reservoir engineering. The latest technologies have been employed to maximize success. Risk analysis, reservoir simulation, three dimensional seismic (3D) interpretation, core analysis, outcrop analysis, and subsurface e-log analysis are the tools that have been utilized to generate a collective evaluation of this world class gas reserve.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado