Abstract

Direct Quadrupole Mass Spectrometers (DQMS) are being deployed in exploration drilling to collect mud gas geochemistry data. Crown Geochemistry, Inc. (tm) has been using the Divining Quad 1000 (tm) from Fluid Inclusions Technologies, Inc. (tm) in the field since 2003. This technology is scheduled to be introduced by Dr. Don Hall of Fluid Inclusion Technologies (F.I.T.) Inc. in a prior session.

This is a no risk, low cost new technology which provides advanced gas analysis while drilling. These useful applications are discussed to exemplify the nature of a few of the applications which this technology has helped to make possible for general use in modern exploration:

1. Compartmentalization: By defining coarse sections of generally similar geochemistry we have been able to map very effectively for compartmental features. In a nutshell, the horizontal production design could in many cases potentially be improved by setting production stage limits so stages do not comingle footage from broadly dissimilar sections. When cutting vertical section the compartmental features identified often correlate to known lithographic sections and the ability to indicate these transitions can help improve accuracy for standard vertical correlation usage. Peter Moreland of Bill Barrett Resources has given us a copy of his recent oral presentation and permission to recap for this audience that portion which presents our work on two of their wells correlated to FMI logs done subsequently on them.

2. Primary and secondary poro/perm: Depending on the system, more porous rock has easily identifiable data characteristics. Faults, fractured systems, and bedding plane “super conduits” are sometimes quite readily apparent, with vertically sealed systems having one profile and open systems having a profile more or less inverse to that. Drilling induced fractures profiles in laterals and vertical wells are also sometimes easily developed.

3. Drive-by depletions: One customer in the Barnett has offered an example data set for a well that passes in close proximity to existing vertical production. The producing well preferentially draws down lighter gas species surrounding the well bore and this is apparent in the light gas profile for the lateral.

4. Gas composition ratio: While actual production differs from mud gas while drilling we will show that, given the far superior quality of DQMS-derived data, we can estimate eventual production character reasonably well. Production characteristics vs. chemistry profile of the mud gas will be presented for several wells.