Reservoir pressures observed during the first infill drilling phase confirmed that the initial wells, some of which had been producing for nearly 20 years, were not adequately draining the reservoir. Also, during the late 's and early 's more efficient hydraulic fracturing fluids were introduced which should have presumably increased the drainage area of the wells and resulted in higher gross ultimate recovery GUR from the wells. In the Gas Research Institute GRI showed interest in working with a producer to better characterize the Cleveland formation so that the best fracturing technique could be determined.
Subsequent joint research with the GRI and Maxus, the predecessor to Midgard, resulted in a better understanding of the Cleveland and the development of the fracturing techniques that are in use today. These changes are expected to result in higher recovery from the wells than would otherwise be obtained.
The research also determined that a minimum of acre spacing would be required in most areas to efficiently drain the Cleveland formation. These data were taken to the Texas Railroad Commission RRC and field rules were changed to permit optional acre units. Sign In or Register. Advanced Search. Sign In. Skip Nav Destination Proceeding Navigation.
Close mobile search navigation. All Days. Previous Paper Next Paper. Article Navigation. Distinctive formation-thickness trends help document Cleveland paleophysiography and provide evidence of syndepositional faulting, flexure, and differential subsidence that markedly affected relative sea level. The unit thickens eastward toward the deep Anadarko Basin and reaches a maximum thickness of about ft in southwestern Hemphill County. Depositional patterns were controlled by 1 a paleohigh in the west part of the study area east flank of the Cimarron Arch that separates siliciclastic facies from carbonate-dominated Cleveland of the Kansas Shelf, 2 subsidence of two subbasins within a northwest-trending half graben bounded by a syndepositional fault system on its south edge and a monoclinal flexure to the north, and 3 an irregular stepped depositional shelf controlled by differential subsidence of an underlying Oswego limestone buildup.
The Desmoinesian Oswego limestone and Marmaton Group undivided and the Missourian Cleveland and Kansas City Formations were examined in the context of their sequence stratigraphic framework. Khodabakhshnejad, Arman MicroSeismic, Inc. Fontenot, Andrew MicroSeismic, Inc. Abstract The main goal for an operator developing an unconventional reservoir project is to maximize NPV per acre by optimizing its completion strategy.
This can be achieved by applying a comprehensive approach that accounts for key well treatment controlling parameters, their impact on the future production performance, and economic uncertainty. In this work, we developed and applied a workflow to explore the impact of various completion parameters and determine the completion strategy with the maximum economic gain.
The workflow integrates petrophysical well log and core data, along with PVT lab experiments with normalized permeabilities calculated from microseismic attributes to initialize the reservoir model. The reservoir model is then calibrated using actual field data to generate a history matched model. Since this model is developed based on microseismic data and represents a realistic network of fractures created during stimulation, it can be further used to analyze the impact of main completion parameters, well spacing and configuration, on the production performance of the wells.
The workflow is applied to three wells drilled in a gas reservoir in the Marcellus Shale. Because abundant field data were available, we can be certain that the calibrated reservoir model accurately matches the reservoir behavior. Detailed analysis of the reservoir model shows the presence of undepleted zones which indicates the current well spacing is too wide. However, the frac hits recorded through microseismic monitoring and pressure interference with nearby wells suggests a tighter well spacing will result in energy loss and over-stimulation.
Therefore, an economic analysis is used to evaluate the various well spacing and configuration scenarios and their implications in terms of cost-benefits. Various well spacing scenarios are created for the original and the proposed chevron pattern well configurations. For each scenario, the EUR, NPV per well, and NPV per acre are calculated to represent maximum gas production, the overall profitability of the pad, and the economic success of the project, respectively.
Three gas price scenarios are used for calculation of the NPV's to analyze the impact of the market condition on the economics of the project. The analysis demonstrates that tighter well spacing, independent of gas price, leads to the improved NPV per acre, reduction of EUR, and an increase in well communication as shown by the newly developed well communication index.
The models reveal that a monotonic relation between well spacing and NPV per acre does not exist due to the complex nature of the created fracture network and competition between two opposite factors: frac hits that arises at tighter well spacing and unstimulated zones that diminish. We showed that obtaining optimized well spacing and configuration could only be achieved through applying a comprehensive workflow that not only accounts for the impact of various well design and configuration parameters on production but also their economic implications defined in terms of NPV per acre.
It is important to note that the integration of microseismic data was essential for the success of the workflow since it provides a realistic picture of the pathways connecting the adjacent wells which facilitate well communication. OnePetro March, Recent casing failures in the Granite Wash play in the western Anadarko Basin have sparked deep concerns to operators in North Texas and Oklahoma.
Hydrostatic tests made in the field show that present API standards do not assure adequate joint and bursting strength to meet deep-well requirements. Past and present literature has been infested with numerous casing failures incidents.
Despite the extensive documentation and recommendations, a mounting trend of failure is still on the rise. In an attempt to find possible solutions for these failures, this study is a continuation of an on-going effort to minimize the likelihood of failure using Data Mining and Machine Learning ML algorithms.
The study applied both descriptive visual representations such as Mosaic and Box Plots and predictive algorithms including Artificial Neural Networks ANN and Boosted Ensemble trees on eighty land-based wells, of which twenty possessed casing and tubing failures.
The study used a predictive analytics software and python coding to evaluate twenty-six different features compiled from drilling, fracturing, and geologic data.
This work attempts to shed light on operational problems and implement a Data Analytic approach to find out the possible factors contributing to casing failures using both descriptive and supervised ML algorithms.
OnePetro December, From molecules to megawatts, and deep sea to the cloud. The discovery is a pellet, self-sealing with a liquid core of either bitumen or heavy oil within a super-viscous, semi-solid, or solid skin that reduces the chance of a damaging spill during transport.
The pellets can be designed to be buoyant and safe if they are spilled into the environment by incorporating agents within the pellets, like gas bubbles, catalysts, and solvents.
Their outer coating is unreactive, making them much less likely to cause environmental damage than a liquid heavy oil or bitumen spill. The sale would be held in March and is attempted to revive interest in a sector that has been reeling since oil prices fell sharply beginning 3 years ago. Although large-scale gas production started in , the regional stratigraphic, depositional, and structural settings of the Cleveland are poorly known.
Reservoir facies of the predominantly siliciclastic Cleveland Formation, in part, were deposited as a series of three eastward-prograding, probably wave-dominated deltas composed of in ascending sequence prodelta, distal delta-front, and proximal delta-front deposits.
An upward-fining fluvial sandstone occurs in one stratigraphic zone in the middle Cleveland throughout most of the study area.
Distinctive trends of thickness variation record elements of the paleophysiography of the Cleveland depositional area and evidence of syndepositional faulting, flexure, and marked differential subsidence.
Depositional patterns were controlled by 1 a paleohigh in the western part of the study area eastern flank of Cimarron arch that separates siliciclastic facies from carbonate-dominate Cleveland of the Kansas shelf, 2 subsidence of two subbasins within a northwest-trending half-graben bounded by more » a syndepositional fault on its southern edge and a monoclinal flexure on the north, and 3 a two-tiered depositional shelf that reflects differential subsidence of an underlying Oswego Limestone buildup.
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