Integration of seismic inversion products for challenging turbidite modelling

Modelling Matters undertook a full field static modelling project for Otto Energy in preparation for the field development plan for the Galoc Field Phase 2 development in the North West Palawan Basin, offshore Philippines. This piece of work assisted the successful Final Investment Decision taken in September 2012.

The main objective of the reservoir modelling was the construction of a reference case model in order to estimate the hydrocarbons in place and provide the reservoir engineer a model from which to estimate the incremental reserves and extend the field life with the planning of two additional development horizontal wells. An uncertainty matrix and associated Tornado plot were generated from sensitivity analysis, which highlighted that structural uncertainty had the main impact on volumes in place. Consequently, representative low and high structure case models were generated for simulation by the reservoir engineer.

A second phase of the project included the incorporation of a newly acquired 3D PSDM seismic data set for the update of the structural and stratigraphic model. The complicated lobate depositional setting of the Galoc turbidites were modelled through the inclusion of inversion volumes which allowed the identification of internal reservoir architecture and helped in the construction of robust facies and petrophysical properties. The inversion cube was used as a secondary variable to condition the population of the porosity. The Petrel uncertainty and workflow manager assisted in the generation of P10, P50 and P90 cases in order to refine the development well planning. 

Development Geology / Reservoir Modelling

Otto Energy engaged Modelling Matters to deliver a 3D static model of the Galoc field, plus uncertainty analysis. The geological model was a key element of the proposal to drill 2 further horizontal development wells in the field. Modelling Matters provided a professional and knowledgeable geological modelling service with good internal QC, documentation and handover.

Nick Pink
Subsurface Manager
Otto Energy

Geomodelling for gas storage at Santos.

Construction of base case 3D geological models of several conventional gas reservoirs for the purpose of investigating gas storage. All available subsurface information, including seismic, well log and production data, was integrated in order to obtain the best understanding of reservoir flow units, their extent and connectivity.

The key components of the model build included the creation of the structural framework, incorporating major unconformity surfaces and localized correlation of flow units. Facies and petrophysical modelling was also systematically incorporated in order to honour the volumes previously produced from the different reservoir pools.

Development Geology / Reservoir Modelling

“I have known Elliott for over 6 years and I first met him when he was working for Roxar. In the last year Elliott has been working in our group as a development geologist modelling our coal seam gas and conventional assets. As always I have found Elliott easy to work with and someone who focuses on the essential tasks to ensure the job is completed. He was able to balance his work between two different models as well as keep his leaders informed of progress. His knowledge of geological modelling and his ability to learn new techniques proved invaluable to our project and to help us keep on track with our milestones. It is with great pleasure that I recommend Elliott.”

Huw Mason
Team Leader Underground Gas Storage
Santos

Chevron Australia Pty Ltd - Reservoir Modeller/ Snr Development Geologist

The focus of the project was the delivery of a new regional structural framework model, encompassing 4 separate gas fields and surrounding areas. This involved the incorporation of well over 100 faults cutting multiple reservoir units, with over a dozen seismically interpreted horizons provided for inclusion. The framework was used to provide the foundation for individual field scale and regional scale models that assisted with GIIP/reserves estimates, development well placement and progress to FID.

Technical work included review and QC of seismic interpretation horizons and faults, depth conversion of this data, and the generation of horizon surfaces and isochore maps for use during the framework construction. Multiple velocity models were used and structural uncertainty analysed through the generation of low, BTC and high case models. Numerous cross-sections, maps and videos were created for presentation and QC purposes.

Additional work included the facies modelling of the fields, with the use of multi-point statistics and object-based modelling while using seismic attribute cubes as secondary conditioning parameters. Using the workflow manager NTG uncertainty was investigated, with the generation of P10, P50 and P90 properties. Using the statistics established from this work the team was able to sense-check their input settings for their low, BTC and high case models.

Development Geology / Reservoir Modelling

“I have worked with Elliott during his time with Chevron Australia. I found Elliott to be a very competent and professional geologist as well as a very good team player. He was highly regarded for his reservoir modelling skills and made important contributions to the team during his period with Chevron. I would highly recommend Elliott.”

Updesh Singh
Earth Science Advisor
Chevron Australia

The construction of a full-field static model of a CSG field for Santos.

The work scope included the construction of a full-field static model of a CSG asset and associated pad optimisation well design, all as part of the Concept Evaluation & Select process. This involved the incorporation of all available seismic, well log, core, proximate and lab analysis data. The reservoir modelling of the CSG asset was aimed at advancing the field modelling beyond the 2D deterministic and mechanistic mapping approach previously used for estimating volumes, towards the 3D domain through the integration of all available data. Upon completion GIIP volumes were calculated and the model was passed on to the reservoir engineers for dynamic simulation. Reservoir parameter uncertainties were investigated as part of the study in order to ascertain the level of uncertainty associated with the different field parameters and the field as a whole.

Aspects of modelling included, well correlation, mapping, structural framework development, reservoir characterization, volume calculations, uncertainty analysis and well planning. Due to the unconventional nature of CSG fields innovative workflows had to be developed to adapt to the inclusion of the unique CSG reservoir characteristics.

Provided and presented relevant geological work for peer and technical assessment meetings during key stages of the project, and delivered extensive documentation for the official reporting of the project development, including the Concept Evaluation, Concept Select and Field Development Plan technical reports.

Development Geology / Reservoir Modelling

“Elliott worked with us for almost 18 months. He was versatile enough to seamlessly switch from CSG to conventional gas and back and also delivered on a Drill Pad Optimisation project for which he had no prior experience. All work was delivered to a high standard and punctually.” 

Arthur Telesford
Team Leader CSG Field Development Planning
Santos