KEM-07 Geomechanical study - small gas field seismicity in The Netherlands

The objective of this research question is to explore the feasibilities of a physics based, numerical (geomechanical) analysis of the causes of induced seismicity in the small gas fields in The Netherlands.

With the study, we seek to physically explain why seismicity has occurred in certain gas fields, whereas other gas fields remained seismically quiet.

With the results we aim to provide a physical basis for future hazard assessments and seismicity forecasts for small gas fields and thereby improve current practice, which is based on gas field parameter studies and expert judgement.

RESEARCH REQUEST FULL TEXT

The central research question is: why has seismicity occurred in certain gas fields, whereas other gas fields remained seismically quiet? The objective was to develop a physics-based numerical based 2D geomechanical analysis method of induced seismicity, which can also be used in scenarios that lie outside the range of previous experience.
A rational quantitative model, based on sound principles of rock mechanics, was developed. The final report describes the geomechanical model approach followed and results obtained using it.

RESEARCH PROJECT FINAL REPORT

The studies shows the methodology could be sound providing sufficient and accurate data are available. It is well written and conclusions are clear.

The studies show the methodology could be sound providing sufficient and accurate data are available. The evaluators consider that the report is well written and conclusions are clear.

RESEARCH PROJECT EVALUATION

A rational quantitative model, based on sound principles of rock mechanics, was developed. Although in many cases the required subsurface data were unknown and had to be estimated in a general way, the model showed a large degree of consistency with the observed seismicity results. The model in its current form can successfully identify some fields in which induced seismicity should be expected.

Collection of more reservoir-specific data on fault properties and more dense seismic monitoring will undoubtedly make the predictions more accurate.