What hasn't been done with geophysics?

There are 137 wells in Abab 56 wells in Dewa, and 119 wells in Raja. Haliburton provided no synthetics to accurately tie the geologic interpretation to the geophysical interpretation. Likewise, in Abab there are 8 productive horizons, and Halliburton only evaluated the "A" Sand. In Dewa there are 29 productive reservoirs, and Halliburton looked at 9 of these. In Raja there are 30 productive Reservoirs, and Halliburton looked at 10 and only evaluated 4 of these completely.

Halliburton's evaluation did not include creating a regional structural and stratigraphic framework. All fault interpretation on the workstation was tied to local breaks in producing horizons. Stratigraphy has not been tied to the Haq, et. al. curve, and there is no evaluation of seismic facies, nor associated geomorphology, depositional environments, nor lithologic distributions. The fields probably do not justify the expense of modern 3-D seismic (which Halliburton made), and particularly the 3-D seismic is not justified if this data is not evaluated in detail, which appears to be the case.

For all of Halliburton's work, there was no evidence of detailed seismic attribute analysis and correlation of these seismic attributes with the producing reservoirs. Any reservoir will have heterogeneities, and one of the key benefits of a 3-D seismic survey - regarding reservoir geophysics - is detailed analysis of the spatial extent of the producing reservoirs. The number of undrilled fault blocks, stratigraphic lens from channels and reefs, deeper pay potential, and infill drilling opportunities seem limited in the Halliburton presentation, given the regional context and past production.

What can be done with geophysics?

There are very few areas of the world where there are not immense amounts of data which have not been compltely analyzed, and which if analysized and synthesized into an integrated interpretation would provide new insights into new upside potential. South Sumatra has certainly not been completely evaluated. There are three specific opportunities relative to obtaining and working the geophysical data over the Abab, Dewa, and Raja Fields:

1. Do an integrated interpretation of bypassed, deeper, and upside opportunities within the Abab, Dewa, and Raja Field boundaries;
2. Use an integrated interpretation of the Abab, Dewa, and Raja Fields as an analog for other fields within the South Sumatra Basin which are or will become available for purchase over the next few years; or
3. A combination of both of the above two opportunities.

The existing seismic, well, and production database can be used to create a regional picture relating the three fields. The Poster Cross-Sections prepared with this report can be taken to Kinkos, printed, and evaluated as an initial understanding of the regional context. The regional faulting, which sets up hydrocarbon migration and trapping, needs to be developed in order to proceed with exploitation of these fields. Understanding this regional context will certainly lead to additional opportunities which can be pursued outside of the potential of this production enhancement contract. The structural framework develops in response to stratigraphy and development of the half-grabens in South Sumatra. The regional stratigraphic framework can also be unravelled, tieing down depositional settings and the distribution of source, seal, and reservoir rocks.

There are numerous seismic attributes which can be tied to reservoir sands, and used to predict by-pass and deeper undrilled pays. Prestack analysis of the seismic velocities to look for sags and pull-ups is a logical starting place. Angle Stacks will allow evaluation of AVO (Amplitude-vs-Offset) opportunities. Anisotrophy, as derived from azimuth, will allow identification of reef edges, channels, anything else which affects horizontal velocity distributions. Prestack depth migration will improve the appearance of the seismic data and enhance the possibility of seeing subtle by-pass or missed pays. Integrated reservoir models defining each of the three fields will provide an engineering framework for distributing predicted lithologies, porosities, permeabilities, and fluids. The key is to define the economic viability and limits for pursuing this type of detailed geophysical analysis.

What is the upside potential?

There appears to be a channel under the Dewa flat area to the NW of the field in what I called a "MiniBasin." This has the potential of being a quarter the size of the existing field. As described above, there are typically bypass and deeper pays that can be pulled out of these types of fields. The key advantage is two of the fields have modern 3-D seismic surveys, which can be worked in detail to generate a set of ranked opportunities. Turning this field around also holds the potential of getting similar contracts for other fields in the vacinity.

Dewa has the most potential, Raja is next, and, of the tree fields, Abab seems to have the least potential. There was not enought time in the two days of evaluation to quantify the upside potential.