OVERVIEW

The purpose of this chapter is to provide readers with a convenient reference for production geology as it relates to the petrophysicist's daily tasks, though not intended to be a comprehensive guide to the wider discipline. The interface between the petrophysicist and production geologist is crucial in ensuring that:

• Wells are proposed and drilled in optimum locations

• The correct operational decisions are made while the well is drilled

• The field model makes optimal use of the available well data

• Production from the well can be properly understood in a structural context

For this interface to work well, it is essential that both discplines have a working understanding of each other and a common terminology.

The primary duties of the production geologist are as follows:

1. Correlate all the available well data within the production area, providing a logical and consistent formation designation scheme.

2. Prepare, in conjunction with the seismologist, geological subsurface interpretations comprising subsurface maps of key horizons and cross sections.

3. Update subsurface interpretations as new well/seismic data become available.

4. Advise on selection of new well locations.

5. Determine the gross bulk volume (GBV) of the reservoir, which may be used, in conjunction with data provided by the petrophysicist, to determine net pore volume (NPV), hydrocarbons initially in place (HIIP), etc. Such models may be either deterministic (i.e., using fixed distributions of reservoir properties) or probabilistic (i.e., using probability distributions for reservoir properties).

6. Create an upscaled subsurface model in digital format that may be exported to the reservoir simulator and used...