Master of Science / Department of Geology / Abdelmoneam Raef / Recently, South Rub’ al-Khali Company Limited (SRAK) acquired a preliminary survey in the Saudi’s oil producing area to develop a feasible new hydrocarbon indication and monitoring (I & M) device using low frequency seismic signals. Based on broadband seismometer data, the new Hydrocarbon I & M might predict the possibility of a hydrocarbon basin underneath by way of evaluating the received spectra for an additional energy shell between 2.0-6.0 Hz. Such a study is also referred to as hydrocarbon microtremor analysis and recently some contracting geophysical service companies offer such studies. This report will concentrate on the hydrocarbon microtremor analysis of synchronized signal of one frequency and an extra re-determination possibly at a separate location. The paper reports on several critical likely misconceptions and examines repeatability of hydrocarbon microtremors. This work indicates that signal generated by manmade operations can yield same tremor as that assumed for hydrocarbon reservoirs. Equally important, the presence of surface waves generated by anthropogenic signal indicates frequency limits ranging from 1 to 10 Hertz as a result of isolated surface waves. The difficulty of isolating any presumed hydrocarbon related tremors from ambient noise hamper efforts of understanding and applying microseism signals to hydrocarbon exploration and monitoring. Repeatability study by Peter, H. & Sascha, B. (2008) raised questions regarding the source of hydrocarbon microtremors. For improved chances of isolating the implied hydrocarbon microtremors from manmade tremors and near-surface impacts, the data require precise recording based on three metrics, frequencies above 3 Hz should be conserved, highly sensitive seismometers should be engaged, and the data registering time should be enough to register ‘tremor-free’ readings.

Master of Science / Department of Geology / Matthew W. Totten / Ness County has contributed 30 billion barrels to Kansas oil production since 1995, and has been an actively developing county in oil activity. The focus of this research project is to identify the reservoir qualities that make Mississippian-aged production favorable. Modern day logging techniques and seismic data allow specialists to seek out subtle heterogeneities to an oil producing formation once thought to be homogenous. Having success with horizontal drilling in other locations worldwide, large oil companies have acquired tens of thousands of acres with the intentions of drilling into the Mississippian, although some have recently backed out of the area. While some horizontal wells are producing today, complications with the compartmentalized, relatively thin Mississippian producing zones and short production longevities make horizontal drilling a high risk technique. Better understanding favorable reservoir qualities are essential for future production and development of oil fields in Ness County. This case study utilizes different variations of post and pre-stack 3D and 2D seismic data shot on about 3,200 acres spanning over 8 sections located in northwestern Ness County. The physical and chemical properties associated with the Mississippian formation in this area can be better analyzed with different methods for processing seismic data. Raw seismic signatures show little variation within the Mississippi Lime/Dolomite. Utilizing Seismic attributes derived from raw data may bring certain featured hydrocarbon bearing zones into view. Attributes such as curvature and coherency aid in interpreting physical features within the study area while spectral decomposition, amplitude, instantaneous frequency, and instantaneous Q hold detailed signatures dependent upon rock properties.

Master of Science / Department of Geology / Matthew W. Totten / A 3D seismic survey was conducted on Beauchamp, Beauchamp North and Beauchamp Northwest fields, which are located in Stanton County, southwest Kansas, by Berexco, Inc. Stanton County is situated on the Hugoton embayment which is the shelf of the Anadarko basin. The producing formation in this area is the Morrow formation, which is the lower Pennsylvanian period. The Morrow formation is mostly a clastic unit and its base was transgressive marine. It is considered an unconformity lying on the Mississippian rocks. Wide geologists agreed with the name of Morrow as name in the rock stratigraphic sequence in the study area (Forgotson, et al., 1966). "The Morrowan series is defined as the interval between the base of the Atokan Thirteen finger limestones and the top of the pre-Pennsylvanian unconformity" (Puckette, et al., 1996). The depositional environment of upper Morrow Formation in western Kansas, according to Sonnenberg (1985), Krystinik et al (1990), was a valley-fill deposit. The purpose of this study is to focus on detecting valley-fill sandstone in the study area by using appropriate seismic attributes. Coherence and discontinuity along dip succeeded to map incised valley-fill sandstone width. On another hand, spectral decomposition displayed subtle changes in incised valley thickness. Positive curvature shows valley edges in moderate resolution, but the most negative curvature wasn't clear enough to display the valley-fill sand. The result of RMS amplitude and average energy attributes results were almost the same. They exhibited four areas of high amplitude and energy in the valley which may indicate the presence of hydrocarbon. Sweetness and envelope amplitude both detected the valley in the study area. A gamma ray cross section shows that there are sequences of incised valley-fill sandstone which are sandstone A, B, C and D of the upper Morrow formation. Johns 2-12 well is producing oil from lower Morrow and sandstone A, thus the valley in the study area may produce oil from Sandstone A or B as RMS amplitude and average energy showing high amplitude in four areas in the valley.

Master of Science / Department of Geology / Matthew W. Totten / 3D seismic surveys have become the backbone of many exploration programs because of their high resolution and subsequent success for wildcat test wells. There are occasions when the predicted subsurface geology does not agree with the actual geology encountered in the drilled well. A case in point occurred during the drilling of several wells based upon a 3D seismic survey in Ness County, Kansas, where the predicted Cherokee Sand did not meet the expectations. By better understanding the subsurface geologic features in the subject area, this study will attempt to answer the question “what went wrong?” Seismic attribute analysis workflow was carried out and the results were correlated to the available geological and borehole data within the survey boundaries. The objective of running this workflow was to describe facies variations within the Cherokee Sandstone. Correlations between seismic attributes and physical properties from well data were used to define these variations. Finally, Distributions of the seismic facies were mapped to predict the distribution of potential reservoir rocks within the prospect area.

Master of Science / Department of Geology / Matthew Totten / Due to their high resolution and established success rates, 3D seismic surveys have become one of the most important tools in many hydrocarbon exploration programs. Basic interpretation of seismic reflectors alone, however, may result in inaccurate predictions of subsurface geology. Historically, seismic attributes have played a particularly important role in the characterization of the lithological and petrophysical properties of hydrocarbon reservoirs in Kansas channel fill lithofacies. Integration of an analysis based on post-stack seismic attributes may drastically reduce the chances of drilling in unsuitable locations. Previous theses have focused on establishing a suitable 3D seismic attribute analysis workflow for use in the determination of hydrocarbon production potential in areas of Ness County, Kansas, USA (Abbas, 2009; Phillip, 2011). By applying a similar workflow in the analysis of additional 3D seismic and well log data obtained from a nearby area in Ness County, and comparing those results to existing borehole and production data, this study seeks to test the hypothesis that seismic attribute analysis is a crucial component in the delineation of heterogeneous reservoir stratigraphy in Kansas lithologies. Time-structure maps, in addition to time slices of several 3D seismic attributes including amplitude attenuation, acoustic impedance, and event continuity all seem to indicate that five previously drilled dry wells within the study area were outside the boundary of a meandering, Cherokee sandstone body of potential reservoir quality. Additionally, comparisons of the results of this research to previous studies conducted in Ness County have provided an opportunity to assess, and potentially contribute to, paleodepositional interpretations made through the utilization of a similar workflow (Raef et al., in press). The results of this study seem to support a broadly NE-SW trending meandering channel system, which is in agreement with the interpretations of Raef et al., and the findings of Ramaker (2009).

Master of Science / Department of Geology / Abdelmoneam Raef / This research presents a workflow integrating several post-stack seismic attributes to assist in understanding the development history of Weirman Field, Ness County, KS. This study contributes to shaping future drilling plans by establishing a workflow combining analysis of seismic attributes and well cuttings to locate a channel fill zone of better reservoir quality, and to highlight reservoir boundaries due to compartmentalization. In this study, I have successfully outlined a fluvial channel, which is expected to be significantly different in terms of petrophysical properties. The Pennsylvanian aged Cherokee sandstones that potentially comprise channel fill lithofacies, in this study, have been linked to oil production throughout the state of Kansas. It is important to understand channel sandstones when evaluating drilling prospects, because of their potential as an oil reservoir and unpredictable shapes and locations. Since their introduction in the 1970s, seismic attributes have become an essential part of lithological and petrophysical characterization of hydrocarbon reservoirs. Seismic attributes can correlate to and help reveal certain subsurface characteristics and specific geobodies that cannot be distinguished otherwise. Extracting and analyzing acoustic impedance, root-mean-square amplitude and amplitude attenuation, guided by a time window focused on the top 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. To form a better understanding of these seismic attributes, this study combined certain attributes and overlayed them in partially transparent states in order to summarize and better visualize the resulting data. A preliminary study of spectral decomposition, which was introduced in the late 1990s, was preformed, and a more in-depth study of this multi-resolution attribute is recommended for future study of this particular field. This study also recommends integrating the revealed compartmentalization boundary and the seismic channel-facies framework in future drilling plans of Weirman Field.

Master of Science / Department of Geology / Abdelmoneam Raef / In this study, laboratory measurements of ultrasonic frequency P- and S-wave velocities were collected and analyzed from two sets of cores. The first set is from a near surface study in southeastern Kansas, and the second set was from the deep subsurface and obtained from a newly drilled well (Wellington KGS 1-32) in Sumner County, KS. Ultrasonic velocities acquired from the second set of cores were then compared with in situ sonic and dipole sonic frequencies of P- and S-waves from well logs. Well log data, core data, and ultrasonic velocity measurements were integrated for Gassmann fluid replacement modeling. The understanding of the velocity and elastic moduli variations at ultrasonic frequencies, along with the comparison of well log velocities can potentially provide improved understanding to establish a beneficial calibration relationship. It could also allow for estimation of shear wave velocities for wells lacking dipole sonic log data. The ability to utilize cost-effective ultrasonic measurements of velocities and elastic moduli in the laboratory, for fluid replacement modeling (Gassmann) in CO[subscript]2-sequestration, as well as, enhanced oil recovery (EOR) projects, would be a significant advance. Potential alternative use of ultrasonic velocities for determining the effects of fluid replacement using Gassmann modeling, when log data is lacking, is an ongoing effort. In this study, the fluid replacement modeling is executed based on sonic and dipole sonic P- and S-wave velocities and compared with results from theoretical modeling. The significance of this work lies in the potential of establishing a calibration relationship for the representative lithofacies of the carbon geosequestration target zone of the Wellington KGS 1-32 well in Sumner County, and enabling the use of ultrasonic measurements of body wave velocities and elastic moduli in Gassmann fluid replacement modeling. This work, when integrated with continuing effort in mapping lithofacies of the Arbuckle and Mississippian groups, would potentially be of great importance to fluid flow simulation efforts and time-lapse seismic monitoring. This study will utilize Gassmann modeling and a range of measurements and data, which include: well logs and ultrasonic laboratory P- and S-wave measurements and core analysis data.

Master of Science / Department of Geology / Abdelmoneam Raef / Seismic reservoir characterization and prospect evaluation based 3D seismic attributes analysis in Kansas has been successful in contributing to the tasks of building static and dynamic reservoir models and in identifying commercial hydrocarbon prospects. In some areas, reservoir heterogeneities introduce challenges, resulting in some wells with poor economics. Analysis of seismic attributes gives insight into hydrocarbon presence, fluid movement (in time lapse mode), porosity, and other factors used in evaluating reservoir potential. This study evaluates a producing lease using seismic attributes analysis of an area covered by a 2010 3D seismic survey in the Morrison Northeast field and Morrison field of Clark County, KS. The target horizon is the Viola Limestone, which continues to produce from seven of twelve wells completed within the survey area. In order to understand reservoir heterogeneities, hydrocarbon entrapment settings and the implications for future development plans, a seismic attributes extraction and analysis, guided with geophysical well-logs, was conducted with emphasis on instantaneous attributes and amplitude anomalies. Investigations into tuning effects were conducted in light of amplitude anomalies to gain insight into what seismic results led to the completion of the twelve wells in the area drilled based on the seismic survey results. Further analysis was conducted to determine if the unsuccessful wells completed could have been avoided. Finally the study attempts to present a set of 3D seismic attributes associated with the successful wells, which will assist in placing new wells in other locations within the two fields, as well as promote a consistent understanding of entrapment controls in this field.

Master of Science / Department of Geology / Matthew Totten / The Petersilie oil field in Ness County, Kansas produces out of the Mississippian System, a reservoir composed mainly of shallow water carbonates, at depths of around 4375 ft (1334 m). The lithology of the field ranges from limestone to dolomite, to interlaminated limestone-dolomite beds. Chert is commonly found throughout. Petersilie field lies to the west of the Central Kansas Uplift, and to the east of the Hugoton Embayment. The field saw much drilling activity in the 1960’s, when it reached a production peak of nearly 378,000 barrels of oil per year. Production declined swiftly after that until the late 1990’s, when waterflooding was successfully employed. In this study, a reservoir model was produced for the Mississippian as it occurs in Petersilie field using the Department of Energy’s EdBOAST reservoir modeling software, with the intent of providing a reference for future drilling activity in the Mississippian and determining reservoir characteristics that may have contributed to the effectiveness of waterflooding in this area. The reservoir model was checked by simulation with a companion reservoir simulator program, BOAST 98. Subsequent comparison of simulated and actual oil production curves demonstrates the reliability of well log and drill stem test data for the field and proves the reservoir model to be a good fit for the Mississippian in Petersilie. Production curve analysis of Petersilie indicates the field was an ideal candidate for waterflooding because it has a solution-gas drive mechanism. As the field approached depletion from primary recovery, oil saturations remained high. Petersilie also exhibits high porosity and good permeability. The BOAST software was found to be an effective and inexpensive means for understanding the Mississippian reservoir in central to south-central Kansas. It was determined that BOAST has potential for practical use by smaller independent oil companies targeting the Mississippian in Kansas.

Master of Science / Department of Geology / Abdelmoneam Raef / Amid increasing interest in geological sequestration of carbon dioxide (CO2), detailed rock formation characterization has emerged as priority to ensure successful sequestration. Utilizing recent advances in the field of 3D seismic attributes analysis, offers improved opportunities to provide more details when characterizing reservoir formations. In this study, several post-stack seismic attributes integrated with seismic modeling for highlighting critical structural elements and petrophysical facies variation of rock formations at Wellington and Anson-Bates fields, Sumner County, Kansas. A newly acquired 3D Seismic data set and several geophysical well logs are also used to achieve the objectives of this study. Results sought in this study are potentially important for understanding pathways for CO2 to migrate along. Seismic amplitude, coherency, and most negative curvature attributes were used to characterize the subsurface for structural effects on the rock formations of interest. These attributes detect multiple anomaly features that can be interpreted as small throw faults. However, in this study, there is a larger anomalous feature associated with the Mississippian formation that can be interpreted as a small throw fault or incised channel sand. Determining which of the two is very important for flow simulation models to be more exact. Modeling of the seismic was undertaken to help in the interpretation of the Mississippian amplitude anomaly. An artificial neural network, based on well log porosity cross-plots and three seismic attributes, was trained and implemented to yield a seismic petrophysical facies map. The neural network was trained using three volume seismic waveform attributes along with three wells with difference in well log porosity. A reworked lithofacies along small throw faults has been revealed based on comparing the seismic structural attributes and the seismic petrophysical facies. Arbuckle formation characterization was successful to a certain degree. Structural attributes showed multiple faults in the northern half of the survey. These faults are in agreement with known structure in the area associated with the Nemaha uplift. Further characterization of the Arbuckle was hindered by the lack of well data. This study emphasizes the need for greater attention to small-scale features when embarking upon characterization of a reservoir for CO2 based geosequestration.