Subsurface Technologies
ADCO is evaluating a number of technologies that will improve forecasting confidence in the areas

ADCO is evaluating a number of technologies that will improve forecasting confidence in the areas of well placement, location of fluid volumes, high resolution sequence stratigraphy and history matching, in addition to maturing EOR concepts & better characterizing our reservoirs & fluids.

4D Seismic Permanent Reservoir Monitoring (PRM) (TRL 5-7):

A feasibility study has been performed for CO2 Pilots in one of our Assets which showed that in order to monitor CO2 WAG flood fronts using 4D seismic, buried, permanent sources and sensors will need to be deployed.  Similar studies have recently reinforced this in other Assets. After completion of the feasibility studies, field tests will be required prior to deployment of the equipment for pilot monitoring.

 

Establish Stratigraphic Framework in Bu Hasa (TRL 8-9):Following a software trial in 2012 to better pick sequence stratigraphy, a re-evaluation of our major reservoirs is being undertaken using climate stratigraphy technology. This is allowing improvement of the existing sequence stratigraphic models and better correlation of reservoirs on a field scale as a structure for future static model update. Further opportunities across ADCO are being identified to aid with improved correlation in reservoir models.

 

Forward Modeling of Facies Distribution (TRL 8-9):

Using the sequence stratigraphy framework derived from the stratigraphy log project & the results of high resolution stratigraphy descriptions in core, it is planned to establish the distribution laterally and in time of facies described in core. The objective is to reduce the current over-reliance on using multivariate statistical techniques to predict facies and geostatistics to predict their distribution, and aid in building a more geological representative static model.

 

Novel History Match Optimisation (TRL 7-9):

Newly developed software codes are being trialled for history match optimization. History match optimization typically uses a deterministic approach for history matching which provides one history match from one geological realization. The new method is grounded in ensemble based methods and uses a full range of geological realizations & quantifies uncertainty based on a full range of matched models, allowing for an accurate evaluation of the uncertainty of our forecasts. The idea is to significantly improve the quality of history match, improve the reliability of production forecasts with proper quantification of the uncertainty, which empowers the use of production forecasts as key input to development planning and operational decisions. It is planned to conduct a trial on an updated reservoir simulation model by Q3, 2016.


Spectral Noise Log Reservoir Characterisation (TRL 4-9): 


Spectral noise logging (SNL) has proved very useful in the ingress/egress of fluids from/to the borehole, static reservoir pressure analysis, flow rate determination and permeability assessment.  ADCO has initiated a laboratory measurement technique that enables downhole noise spectra to be calibrated to known rock types and their petrophysical parameters.  This technology is now being implemented in the Asset teams.
Single Well Chemical Tracer Test (SWCTT) (TRL 8-9): ADCO conducted the first SWCTT trial onshore UAE in Q4, 2015.  Eventually, three miscible displacement processes; low salinity water injection, CO2 injection and rich hydrocarbon gas injection tests will be performed in 9 wells after a baseline residual oil saturation has been established in each test zone so that the incremental value of each EOR process can be assessed.

Single Well Chemical Tracer Test (SWCTT) (TRL 8-9):

 ADCO conducted the first SWCTT trial onshore UAE in Q4, 2015.  Eventually, three miscible displacement processes; low salinity water injection, CO2 injection and rich hydrocarbon gas injection tests will be performed in 9 wells after a baseline residual oil saturation has been established in each test zone so that the incremental value of each EOR process can be assessed.


 

 


 

Advanced SCAL Tests (TRL 4-9):

The primary objective is to improve design and acquisition of good laboratory data to complement other measurements/tests, and wherever appropriate improve static and dynamic models with real reservoir core data at representative conditions. Over a dozen tests have been conducted to mimic CO2 and CO2 WAG injection, and assess comparisons with miscible or near miscible lean and rich gas injections.
Typically the studies have been QC’d with compositional simulation studies to assess experimental uncertainties with respect to pressure changes, hydrocarbon production, remaining residual oil and effluent characterization. Assets have found data very useful to assess breakthrough times, EOR recovery potentials and to validate the developed Equation of State to improve the dynamic modelling processes.

Reservoir Characterization & DRP (TRL 4-8): 


 ADCO has been at the industry forefront in using Digital Rock Physics (DRP) based techniques. Issues related to porosity types, microporosity, permeability variations, electrical parameters like ‘m’ / ‘n’, elastic properties like Vp / Vs / shear / bulk moduli, multi-phase properties like capillary pressure and relative permeability have been quantified and validated.  Several DRP based projects have been completed to address ADCO business needs in reservoir characterization and to address current uncertainties. Assets have completed novel projects on primary drainage, water-oil relative permeability, DNA for reservoir core characterization, sensitivity studies on LowSal optimization and to address the impact of pore geometry on elastic properties. These results are being calibrated with laboratory results.
ADCO has also partnered with ADNOC/PI/Masdar Institute to further enhance the learnings from this exciting technology.