Geological Cross Sections for the Volve Oilfield

The Volve field  is a 4-way dip closure with the Middle Jurassic Hugin Formation as reservoir. The geologic cross section is an important toot to understand the development of the producing Hugin formation across the Volve Oilfield. It provides important information on the development of the reservoir sand, the expected production behavior, optimizing placement of producers and injectors.

Geological cross sections are graphical representations of vertical slices through the earth used to clarify or interpret geological relationships with or without accompanying maps. As with other tools applied to petroleum development, cross sections are used to portray geological information in a visual form so that reservoir characteristics can be readily interpreted. (Reference: AAPG)

Sumary

• Software
• Stratigraphy units: Upper Hugin, Middle Hugin and Lower Hugin
• Cross Section Map
• Section 1
• Section 2
• Section 3
• Section 4
• Conclusion

The depth contour map at Hugin Top level for the Volve structure (image below) shows the development of the reservoir sands. The highly faulted anti-cline structure has primary fault trends in the North East – South West and North West-South East directions. The discovery Well 15/9-19 SR was drilled close to the crest of the structure.

It you have access to the RMS based geologic model ad are able to export it to a more open format, kindly contact us.

Software

Logview++ by Firagiel was used to prepare the log database. All the Well logs, Deviation files and Well Tops were loaded into the software to prepare the dataset.

The Deviation data parameters imported are: MD, Inclination and Azimuth. There parameters are available from the End of Well reports provided in the dataset. The TVD is calculated from this dataset and used in preparing the cross sections.

A combined log file incorporating the input and output parameters of a Petrophysical analysis is used in this analysis.

Log Alias Parameters: DEPTH, CALI, DRHO, DT, GR, NPHI, RD, RHOB, RS, RT, BVW, CARB_FLAG, COAL_FLAG, KLOGH, PHID, PHIF, SAND_FLAG, SW, VSH, VLITH, DEPTH TVD.

Stratigraphy units: Upper Hugin, Middle Hugin and Lower Hugin

The Hugin formation is divided into three facies – Upper Hugin, Middle Hugin and Lower Hugin. The Thief Zone and the Upper Hugin are separated by the ‘offshore shale’, which is considered a field wide barrier.

Overall reservoir properties on Volve are very good with N/G up to 90%, average porosities of 21% and permeabilities in non-cemented sands varying from 100 mD to up to >10 D (especially in the Thief Zone – Middle Hugin).

Cross Section Map

The sections generated are marked on the depth contour map at Hugin top level. These sections should be able to provide a holistic view of the development of the Hugin reservoir in the Volve Oilfield.

Section 1

In this section, we look at the Wells 15/9-F-15A, 15/9-F-15B, 15/9-F-15C and 15/9-F-4. This is an East-West Section.

The Hugin reservoir almost non existent in the Well 15/9-F-15B. However, there is good development of the reservoir facies close to Well 15/9-F-15C and 15/9-F-4.

Section 2

In this section, we look at the Wells 15/9-F-15C, 15/9-F-12, 15/9-F-14, 15/9-F-15D and 15/9-F-11-T2. This section extends from North east to South West.

The division of the Upper, Middle and Lower Hugin is available in the petrophysical analysis. It is interesting to note that Wells 15/9-F-14, 15/9-F-15D the Hugin formation is encountered twice. This indicates these wells were drilled through a fault with significant vertical throw.

Section 3

In this section, we look at the Wells 15/9-F-1C, 15/9-F-1B and 15/9-F-11A. This section extends from North east to South West.

The division of the Upper, Middle and Lower Hugin is available in the petrophysical analysis. The Well 15/9-F-1C is a geo steered well and hence has a large horizontal displacement. This also passes through a fault and hence the Hugin formation is encountered twice.

Section 4

In this section, we look at the Wells 15/9-F-1A, 15/9-F-1, 15/9-F-1B, 15/9-F-11A, 15/9-F-15D and 15/9-F-5. This is an East-West Section.

It seen that the Hugin formation is absent in the Well 15/9-F-1. In the Well 15/9-F-15D the Hugin formation is encountered twice

Conclusion

These sections provide an insight into development of the Volve Structure and this information is very useful for preparation of static models, field development plans, optimizing completion strategy and for reservoir performance prediction.