Projects

The QI of the Abadan Plain Basin Project

The Quantitative interpretation (QI) of the Abadan Plain project will look at petrophysics and rock physics and perform an inversion to closely examine the relationship between elastic attributes and the lithologies & potential reservoir properties and porosity.
The products of the QI project will facilitate the design of infill drilling programs and finding stratigraphic traps to induce enhanced/increased oil recovery from the reservoir(s). The results of core data analysis will be integrated into this study. For example, calibration of porosity in the Petrophysical evaluation step, calculation of dry bulk modulus and measuring anisotropy parameters in the Rock Physics modeling step.
It is assumed the 3D seismic data will only require standard pre-inversion data conditioning. However, upon inspection, it may be agreed that it would need more fundamental reprocessing, to look at the statics, multiple, noise and velocity model etc., and the data will not be used, but for this initial proposal – standard pre-stack data conditioning will be assumed sufficient.

Phase 1

Comprehensive laboratory studies, petrophysics and rock physics evaluation of core samples (Completed)

  Initial evaluation of cores for samples detection: Results Evaluation and Endorsement
  Geological studies: Results Evaluation and Endorsement
  Samples preparing: Results Evaluation and Endorsement
  Rcal and Scal Core tests: Results Evaluation and Endorsement
  Petrophysical evaluations and rock physics tests: Core Specialist Supervision, Results Evaluation and Endorsement / Cross-Check Analysis of Measurement for 5 Samples by Core Specialist Services Company
  Integration of results and reporting: Attending and contribution in final results evaluation in Technical Panels / Results Evaluation and Endorsement

Phase 2

Processing and QI on 2D-3C Seismic data (area 3) (The processing of 2D-3C data is completed)

  Interpretation and Domain Conversion: Well to Seismic tie (7 wells) / Horizons Picking and TWT Mapping / Velocity Model Building and Domain Conversion / Deliverables, Reporting and Presentation
  Seismic Petrophysics: Petrophysical Evaluation (7 wells) / Rock Physics Analysis (7 wells) / Synthetic Modeling and Analysis (7 wells) / Deliverables, Reporting and Presentation / Petrophysics (Power log) and Rock Physics (RPM) workshop
  AVO analysis: PP AVO Analysis / PS AVO Analysis / Deliverables, Reporting and Presentation
  Seismic Inversion: Post-Stack PP (7 wells) / Pre-stack PP (7 wells) / PP-PS Joint (7 wells) / Deliverables, Reporting and Presentation
  Reservoir Properties Estimation: Porosity Estimation / Fluid Probability Analysis / Lithology (Facies) Estimation / Deliverables, Reporting and Presentation
  3C and Conventional Data Analysis: Performing SDC, AVO, Inversion, Property Estimation on Conventional data / Comparison with Conventional Results / Feedbacks and Roadmap Preparation / Deliverables, Reporting and Presentation / 3C QI and Rock Physics workshop

Phase 3

VSP Processing and Analysis
(Completed)

➥  VSP Processing: Offset VSP (1 well) / Walk-away VSP (1 well) / Deliverables, Reporting and Presentation / Offset and walkaway VSP Processing and Analysis workshop
  Root cause analysis: Modeling / Parameter Optimization / Deliverables, Reporting and Presentation

Phase 4

QI on 2D Seismic Lines (area 2)

➥  Feasibility Study: Evaluation of the 2D data Quality from QI point of view
➥  Seismic Petrophysics: Petrophysical Evaluation (6 wells) / Rock Physics Analysis (6 wells) / Synthetic Modeling and Analysis (6 wells) / Deliverables, Reporting and Presentation
➥  Seismic Data Conditioning (SDC) – 2000 lkm 2D data: Coherent and Random Noise Suppression / Reflector Alignment (Trim, Residual NMO or etc.) / Resolution Enhancement (HDRE and Spectral Bluing) / Offset Scaling / Deliverables, Reporting and Presentation
➥  AVO analysis: AVO Attributes Extraction / Gradient Analysis / AVO class and Zonation / Sweet Spot Detection / Deliverables, Reporting and Presentation
➥  Seismic Inversion: Deterministic Post-Stack Seismic Inversion (10 wells) / Deterministic Pre-Stack Seismic Inversion (Simultaneous and EEI) (10 wells) / Deliverables, Reporting and Presentation
➥  Reservoir Properties Estimation: Porosity Estimation / Fluid Probability Analysis / Lithology (Facies) Estimation / Deliverables, Reporting and Presentation
➥  Domain Conversion: Velocity Model Building and Domain Conversion / Deliverables, Reporting and Presentation

Phase 5

QI on 3D Seismic data (area 1)

➥  Feasibility Study: Evaluation of the 3D data Quality from QI point of view
➥  Seismic Petrophysics: Petrophysical Evaluation (5 wells) / Rock Physics Analysis (5 wells) / Synthetic Modeling and Analysis (5 wells) / Deliverables, Reporting and Presentation
➥  Seismic Data Conditioning (SDC) – 1000 sqkm 3D data: Coherent and Random Noise Suppression / Reflector Alignment (Trim, Residual NMO or etc.) / HVA (Horizon Based Velocity Analysis) / Resolution Enhancement (HDRE and Spectral Bluing) / Offset Scaling / Deliverables, Reporting and Presentation
➥  AVO analysis: AVO Attributes Extraction / Gradient Analysis / AVO class and Zonation / Sweet Spot Detection / Deliverables, Reporting and Presentation
➥  Seismic Inversion: Deterministic Post-Stack Seismic Inversion (10 wells) / Deterministic Pre-Stack Seismic Inversion (Simultaneous and EEI) (10 wells) / Stochastic Post-Stack Seismic Inversion (10 wells) / Stochastic Pre-Stack Seismic Inversion (Simultaneous and EEI) (10 wells) / Deliverables, Reporting and Presentation / HRS AVO, GeoSI, Conditioning, Inversion workshop
➥  Reservoir Properties Estimation: Porosity Estimation / Fluid Probability Analysis (including CCB) / Lithology Estimation / Supervised and Unsupervised Facies Classification / Deliverables, Reporting and Presentation / Property Estimation and Classification Workshop
Interpretation and Domain Conversion: Geobody Analysis and Extraction / Velocity Model Building and Domain Conversion / Deliverables, Reporting and Presentation

It is worth to mention that reservoirs of interest are Ilam, Sarvak, Kazhdumi sands, Gadvan and Fahliyan. In Gadvan, geostatistical inversion should be carried out.
In general, the QI project has been carried out in the form of two major parts of laboratory and seismic studies, in which extensive information was collected and produced as follows.

Laboratory data

➥  Well locations and deviation surveys for the wells in ASCII format
➥  Standard logs for the wells in LAS format (Full Set, FMI, DSI/Sonic Scanner, GR, Resistivity and etc.)
➥  Raw and Processed VSP/Check shot information in SEGY/ASCII format
➥  Formation tops and markers for the wells in ASCII format,
➥  Petrophysical evaluation for the wells in LAS format including e-facies logs,
➥  Permeability logs are necessary for reservoir modeling.
➥  Check shot and/or VSP time-depth table and Raw and Processed VSPs
➥  Reservoir fluid parameters: pressure, temperature, formation water salinity, Gas water ratio, Gas gravity, etc.
➥  Regional and field geological reports
➥  Any other information pertinent to well data processing
➥  All the end of well drilling Reports
➥  Daily drilling reports
➥  Reservoir Fluid Contacts

Seismic data

➥  Results of the 2D-3C processing (Post-, Pre-stacks and velocities)
➥  Available vintages from previous processing of 3D cube and 2D lines in SEGY Format.
     Stacks (full and partial)
     Gathers (PSTM)
     Velocities
➥  Seismic acquisition, processing, interpretation, reservoir characterization reports
➥  Interpreted faults and horizons for conventional 2D and 3D data

Owing to the fact that this project is research-based, we are pleased to list several important technical points where significant innovations have resulted from the progress of this project:

Technical points

1. To integrate Core Analysis and rest of the study via calibrating reservoir rock properties estimated from well logs in order to reduce uncertainty, including Seismic Anisotropy in the study by direct measurement of P-wave and S-wave velocities in three directions, estimating anisotropic ITA parameter useful for non-hyperbolic move out in seismic processing, accurately estimating the bulk modulus of rock dry frame, analyzing the effects of facies and pore types, and evaluating the effects of confining and pore-pressure on elastic properties.

2. To compute Q-1 (Seismic Attenuation) from conditioned logs and seismic data. Q-inverse or seismic attenuation (Q= seismic quality factor) is an important rock and fluid property which affects the quality of seismic volume, can serve as a fluid attribute and is also used in association with other parameters such as anisotropic ITA necessary in non-hyperbolic move out.

3. To process 2D-3C seismic lines and benefit from their complementary effects once integrated, with 3D seismic data, further capturing vast information about reservoir and fluid contents via shear wave splitting observed in PS data, followed by more importantly PP/PS Simultaneous Joint Inversion.

4. To investigate known Rock Physics Templates (RPTs) and define regionally updated RPTs in various lithological units and reservoir fluids in the areas under study applicable to Rock Physics Analysis, EEI Analysis and Client’s bespoke Seismic Inversion

5. To conduct Horizon-based Velocity Analysis (HVA) for accurate estimation of the stacking/RMS velocity at the top and bottom of the inversion intervals and further use it to control interpolation/extrapolation in the Low Frequency Background Model

 

6. To implement a bespoke workflow to detect thin layers among reservoirs of interest, also to enhance seismic frequency bandwidth via tools the like of Spectral Bluing and assess High Dimensional Resolution Enhancement (HDRE) in CWT (Continuous Wavelet Transform) domain for increasing resolution for thin bed analysis

7. To carry out Depth Trend Analysis and verify the onset of geochemical compaction and their effects on Rock Physics Modelling and AVO, AVAz analyses in order to avoid false AVO, AVAz responses.

8. To apply multi-disciplinary approach for investigating tilted Oil-Water Contact and asses various tools such as stacking traces along the same contour at reservoir interface levels or Common Contour Binning (CCB) and Chimney Analysis.

Velocity Modelling Project

Various depth conversion methods have been used in the interpretation processes for several years. Usually, if there is time to conduct projects, different methods are evaluated and error factors are considered with well markers and inconsistent depth maps to select the best velocity model. The necessity of doing this project is that the process of converting to depth and transferring all the data (which have been prepared with great effort over time) to the most accurate location in depth is performed in the best way.
In this project, identifying and using the capabilities of speed modeling software will be considered, and in the form of conducting the project as a pilot and holding a technology transfer course, the solution is to use this software as an alternative to other common methods in the discussion. Depth conversion and related uncertainty analyses are also presented.
Among the applications of this project, it is possible to transfer the knowledge of speed and depth conversion modeling and upgrade technology from the TRL6 level to the TRL9 level, identify the effective elements in the errors of the depth conversion process, provide suitable solutions to reduce these errors, provide suitable solutions for the selection of different methods of speed model construction, and provide appropriate solutions to quantify the uncertainty in the topics of depth conversion.