Reservoir management under geological uncertainty using fast model update

Statoil is implementing "Fast Model Update (FMU)," an integrated and automated workflow for reservoir modeling and characterization. FMU connects all steps and disciplines from seismic depth conversion to prediction and reservoir management taking into account relevant reservoir uncertainty. FMU delivers an ensemble of geologically-consistent...

Quantification of the impact of ensemble size on the quality of an ensemble gradient using principles of hypothesis testing

With an increase in the number of applications of ensemble optimization (EnOpt) for production optimization, the theoretical understanding of the gradient quality has received little attention. An important factor that influences the quality of the gradient estimate is the number of samples. In this study we use principles from statistical...

Mitigation of terrain induced slugging using mixer devices

The present work focuses on experimental evidence of slug mitigation via various devices. The slug mitigation potential of a number of mixers was tested using a laboratory scale air/water setup to compare their effect on the incoming slugs just upstream of the separator inlet. Dedicated methods and key performance indicators were developed to...

Data quality of a low fold seismic survey employing a buried multi-component array at Ketzin

To monitor the migration of the injected CO2 in the Ketzin project (Germany) a permanently buried multi-component seismic array has been installed in August 2009. Besides passive seismic recordings, this monitoring system was used to record data for an active survey carried out in 2009, resulting in a 200 m long 2D seismic line roughly passing...

Towards an integrated workflow for structural reservoir model updating and history matching

A history matching workflow, as typically used for updating of petrophysical reservoir model properties, is modified to include structural parameters including the top reservoir and several fault properties: position, slope, throw and transmissibility. A simple 2D synthetic oil reservoir produced by waterflooding is used to demonstrate issues...

GPR monitoring of oil displacement - A laboratory study

In this paper we present laboratory experiments where we address the Ground Penetrating Radar (GPR) capability of monitoring oil displacement processes in porous media. This has significant applications in near-subsurface environments where remediation of contaminant such as oil-derived liquids is considered one of the major technical,...

Computer modeling and laboratory experiments of a specific borehole to surface electrical monitoring technique (BSEMT)

Geophysical monitoring of the dynamical behavior of subsurface reservoirs (oil, gas, CO2) remains an important issue in geophysical research. A new idea for reservoir monitoring based on electrical resistivity tomography was developed at TNO. The essential element of the so-called BSEMT (Borehole to Surface Electrical Monitoring Technique)...

Passive seismic monitoring in two carbon sequestration sites, a data driven approach

Passive seismic imaging during CO2 injection in geological formations gains more and more interest as part of an integrated monitoring approach. For two EU CO2 storage project sites, RECOPOL - Enhanced Coal-Bed Methane pilot site in Kaniów (Poland) and CO2SINK- CO2 injection in a saline aquifer in Ketzin (Germany), the Netherlands Geological...

Geomechanical modeling of surface uplift around well KB-502 at the in Salah CO2 storage site

Injection of CO2 in the InSalah field has caused uplift of the surface, as observed by satellite geodetic techniques (InSAR). Around one of the wells, KB-502, the uplift shows anomalous behaviour: a two-lobe pattern develops in the direction of the preferred fracture orientation. This indicates the tensile opening of a fracture or a fracture...

A case study of the history matching of a sector of the nome field using the ensemble Kalman filter

In the history matching process reservoir parameters are estimated so they can be further used in a simulator to reproduce the past behaviour of the reservoir. During the last two decades the methodology evolved from manual methods to computer assisted procedures which can handle larger amounts of data. Now, when the computational power has...

A Bayesian belief network approach for assessing the impact of exploration prospect interdependency: An application to predict gas discoveries in the Netherlands

Prospect interdependencies, if present and positively correlated, result in a higher standard deviation of the portfolio volumetric expectation curve, compared to a portfolio with independent prospects. This wider uncertainty range offers options for companies to increase the expected cumulative net present value (NPV) of the exploration...

Influence of ensemble geostatistics on production history matching and prediction at new wells

Automatic history matching techniques such as the Ensemble Kalman Filter (EnKF) have been shown to provide reliable results for matching and prediction at existing wells. It is much less clear if the prediction outside of existing wells improves as a result of history matching. The amount of information in production data on the spatial...