Abdelmoneam Raef

Factor analysis approach for composited ASTER band ratios and wavelet transform pixel-level image fusion: lithological mapping of the Neoproterozoic Wadi Kid area, Sinai, Egypt

In this study, we have adopted an approach for objective optimization of the selection of band ratios in forming Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) band ratio composites, based on factor analysis loadings and specific variances. The factor loadings and specific variances of all 72 possible spectral band ratios of the visible and near infrared (VNIR) and the short-wave infrared (SWIR) of ASTER data from Wadi Kid, southeastern Sinai Peninsula, Egypt, were utilized to construct two separate rankings of band ratios in an ascending manner in order to determine the best ASTER band ratio combinations for lithological mapping in the study area. Two ASTER band ratio composites ((band 6/band 3–band 1/band 3–band 9/band 5) and (8/6–8/7–4/7) in blue–green–red (BGR)) were built, based on the rankings of factor loadings and specific variances, respectively. These two composites were fused together based on a discrete wavelet transform (DWT) decomposition, which enables decomposition of an image into (high-pass) details and (low-pass) approximations at various levels of resolution, resulting in improved lithological discrimination of granitic and meta-sediments rock units and a reduction in the BGR imprints of topographic reliefs.

3D Seismic Attributes Analysis to Outline Channel Facies And Reveal Heterogeneous Reservoir Stratigraphy: Weirman Field, Ness County, Kansas, USA

In this paper, we present a workflow integrating several post-stack seismic attributes to assist in understanding development history of our study area. We also aim to shape future drilling plans by outlining a channel fill zone of better reservoir quality, and to highlight reservoir boundaries of compartmentalization. Extracting and analyzing acoustic impedance and amplitude attenuation, guided by a time window focused on the bottom of the Mississippian formation, resulted in an understanding of the key seismic channel-facies framework and helped to explain some of the disappointing drilling results at Weirman Field. This study recommends integrating the revealed compartmentalization boundary and the seismic channel-facies framework in future drilling plans of Weirman Field.

Repeatability observations from a time-lapse seismic survey

Timelapse seismic surveys are particularly useful for detecting changes in material characteristics. Distinguishing changes in subsurface conditions from noise, source and receiver coupling variability, source wavelet change, and other sources of error related to the dynamics of surface conditions in timelapse seismic images is challenging, at best. The objective of this study is to identify factors that affect repeatability of high-resolution near surface time-lapse seismic data when using a projectile source in unconsolidated sediments and investigate minimizing the effects of these factors. Data for this study were acquired as part of a 2D time-lapse seismic reflection survey in the floodplain of the Rio Grande near Las Cruces, New Mexico. The source was a 30.06 fired into pre-drilled holes in sandy soil; the holes were used for the baseline and eight monitor surveys. Changes in wavelet characteristics clearly indicate that the source signature varied nonlinearly as a function of the number of shots fired downhole. Results indicate that changes in the wavelet become increasingly nonlinear at increasing distance from the source and spectrally degrade with continuous use despite attempts to maintain the same firing conditions. This change through use is caused in part by change in source signature due to degradation of the holes during initial shots. It appears necessary to fire multiple shots downhole prior to acquisition to compact unconsolidated sediments and condition holes to increase repeatability of the data. The number of conditioning shots is likely related to soil conditions (saturation, compaction, clay to sand content, etc.).

Data-driven modeling of heavy oil viscosity in the reservoir from geophysical well logs

ABSTRACT Viscosity is the most crucial fluid property on recovery and productivity of hydrocarbon reservoirs, more particularly heavy oil reservoirs. In heavy and extra heavy oil reservoirs e.g. bitumen and tar sands more energy is required to be injected into the system in order to decrease the viscosity to make the flow easier. Therefore, attempt to develop a reliable and rapid method for accurate estimation of heavy oil viscosity is inevitable. In this study, a predictive model for estimating of heavy oil viscosity is proposed, utilizing geophysical well logs data including gamma ray, neutron porosity, density porosity, resistivity logs, spontaneous potential as well as P-wave velocity and S-wave velocity and their ratio (Vp/Vs). To this end, a supervised machine learning algorithm, namely least square support vector machine (LSSVM), has been employed for modeling, and a dataset was provided from well logs data in a Canadian heavy oil reservoir, the Athabasca North area. The results indicate that the predicted viscosity values are in agreement with the actual data with correlation coefficient (R2) of 0.84. Furthermore, the outlier detection analysis conducted shows that only one data point is out of the applicability of domain of the develop model.

3D Seismic Reflection Amplitude and Instantaneous Frequency Attributes in Mapping Thin Hydrocarbon Reservoir Lithofacies: Morrison NE Field and Morrison Field, Clark County, KS

Thin hydrocarbon reservoir facies pose resolution challenges and waveform-signature opportunities in seismic reservoir characterization and prospect identification. In this study, we present a case study, where instantaneous frequency variation in response to a thin hydrocarbon pay zone is analyzed and integrated with other independent information to explain drilling results and optimize future drilling decisions. In Morrison NE Field, some wells with poor economics have resulted from well-placement incognizant of reservoir heterogeneities. The study area in Clark County, Kanas, USA, has been covered by a surface 3D seismic reflection survey in 2010. The target horizon is the Viola limestone, which continues to produce from 7 of the 12 wells drilled within the survey area. Seismic attributes extraction and analyses were conducted with emphasis on instantaneous attributes and amplitude anomalies to better understand and predict reservoir heterogeneities and their control on hydrocarbon entrapment settings. We have identified a higher instantaneous frequency, lower amplitude seismic facies that is in good agreement with distinct lithofacies that exhibit better (higher porosity) reservoir properties, as inferred from well-log analysis and petrographic inspection of well cuttings. This study presents a pre-drilling, data-driven approach of identifying sub-resolution reservoir seismic facies in a carbonate formation. This workflow will assist in placing new development wells in other locations within the area. Our low amplitude high instantaneous frequency seismic reservoir facies have been corroborated by findings based on well logs, petrographic analysis data, and drilling results.

Rock formation characterization for CO2-EOR and carbon geosequestration; 3D seismic amplitude and coherency anomalies, Wellington Field, Kansas, USA

In this paper, we present a workflow for a Mississipian carbonates characterization case-study integrating poststack seismic attributes, well-logs porosities, and seismic modeling to explore relating changes in small-scale “lithofacies” properties and/or sub-seismic resolution faulting to key amplitude and coherency 3D seismic attributes. The main objective of this study is to put emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2-EOR in preparation for future carbon geosequestration in a depleting reservoir and a deep saline aquifer. The extracted 3D seismic coherency attribute indicated anomalous features that can be interpreted as a lithofacies change or a sub-seismic resolution faulting. A 2D finite difference modeling has been undertaken to understand and potentially build discriminant attributes to map structural and/or lithofacies anomalies of interest especially when embarking upon CO2-EOR and/or carbon sequestration monitoring and management projects.

A new approach for weak time‐lapse anomaly detection using seismic attributes: geology and production data integrated monitoring of miscible flood in carbonates

Since the emergence of time-lapse, TL, seismic technology as a viable element of reservoir management, monitoring production and enhanced oil recovery programs, in carbonates, has been very challenging. Coupled effects of complicated petrophysical and/or lithofacies heterogeneities “difficult to model or image,” low compressibility “high stiffness,” and thinness of carbonates have made seismic monitoring a high-risk component of EOR programs requiring both highly repeatable 4Dseismic acquisition and weak anomaly-sensitive processing and interpretation approaches. Most important is the need to maximize interdisciplinary synergy among all reservoir management team members. In this study, we present a new non-differencing approach called “Parallel Progressive Blanking” (PPB) for detecting time-lapse seismic attributes anomalies. This approach is more efficient than differencing TL attributes and/or data in cases where weak anomalies are concealed by non-repeatable noise. Four 4D-seismic datasets, interpreted seismic lineaments, seismic facies, sedimentological models and production data provided a means of testing and validating the PPB approach of interpreting weak TLseismic attributes of anomalous zones observed during a miscible EOR-CO2 flood. Using four TL-seismic datasets and applying the PPB approach, we have successfully monitored changes in seismic response related to the miscible EOR-CO2 bank in the Hall-Gurney Field in Kansas. A predicted “via reservoir simulation” CO2 breakthrough in April, 2004 in well 12 and an unpredicted delayed response from well 13 have been in compliance with the interpreted spatial outline of the injected CO2 bank. Changes in pump strategies between two seismic surveys resulted in retreating of the CO2 plume. Relatively fine (two months) survey-to-survey time spacing has assisted qualitative estimation of both reservoir heterogeneity and robustness of implementing the PPB approach, furthermore, dynamic flood management was aided by TLfindings.

4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

The objective of this research project is to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in an attempt to observe changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data.