Browsing by Subject "Unconventional Gas"
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Item A Methodology to Determine both the Technically Recoverable Resource and the Economically Recoverable Resource in an Unconventional Gas Play(2010-10-12) Almadani, Husameddin Saleh A.During the past decade, the worldwide demand for energy has continued to increase at a rapid rate. Natural gas has emerged as a primary source of US energy. The technically recoverable natural gas resources in the United States have increased from approximately 1,400 trillion cubic feet (Tcf) to approximately 2,100 trillion cubic feet (Tcf) in 2010. The recent declines in gas prices have created short-term uncertainties and increased the risk of developing natural gas fields, rendering a substantial portion of this resource uneconomical at current gas prices. This research quantifies the impact of changes in finding and development costs (FandDC), lease operating expenses (LOE), and gas prices, in the estimation of the economically recoverable gas for unconventional plays. To develop our methodology, we have performed an extensive economic analysis using data from the Barnett Shale, as a representative case study. We have used the cumulative distribution function (CDF) of the values of the Estimated Ultimate Recovery (EUR) for all the wells in a given gas play, to determine the values of the P10 (10th percentile), P50 (50th percentile), and P90 (90th percentile) from the CDF. We then use these probability values to calculate the technically recoverable resource (TRR) for the play, and determine the economically recoverable resource (ERR) as a function of FandDC, LOE, and gas price. Our selected investment hurdle for a development project is a 20 percent rate of return and a payout of 5 years or less. Using our methodology, we have developed software to solve the problem. For the Barnett Shale data, at a FandDC of 3 Million dollars, we have found that 90 percent of the Barnet shale gas is economically recoverable at a gas price of 46 dollars/Mcf, 50 percent of the Barnet shale gas is economically recoverable at a gas price of 9.2 dollars/Mcf, and 10 percent of the Barnet shale gas is economically recoverable at a gas price of 5.2 dollars/Mcf. The developed methodology and software can be used to analyze other unconventional gas plays to reduce short-term uncertainties and determine the values of FandDC and gas prices that are required to recover economically a certain percentage of TRR.Item Development of an improved methodology to assess potential unconventional gas resources in North America(Texas A&M University, 2007-09-17) Salazar Vanegas, JesusSince the 1970s, various private and governmental agencies have conducted studies to assess potential unconventional gas resources, particularly those resources contained in tight sands, fractured shales, and coal beds. The US Geological Survey (USGS) has assessed the amount of unconventional gas resources in North America, and its estimates are used by other government agencies as the basis for their resource estimates. While the USGS employs a probabilistic methodology, it is apparent from the resulting narrow ranges that the methodology underestimates the uncertainty of these undiscovered, untested, potential resources, which in turn limits the reliability and usefulness of the assessments. The objective of this research is to develop an improved methodology to assess potential unconventional gas resources that better accounts for the uncertainty in these resources. This study investigates the causes of the narrow ranges generated by the USGS analyticprobabilistic methodology used to prepare the 1995 national oil and gas assessment and the 2000 NOGA series, and presents an improved methodology to assess potential unconventional gas resources. The new model improves upon the USGS method by using a stochastic approach, which includes correlation between the input variables and Monte Carlo simulation, representing a more versatile and robust methodology than the USGS analytic-probabilistic methodology. The improved methodology is applied to the assessment of potential unconventional gas resources in the Uinta-Piceance province of Utah and Colorado, and compared to results of the evaluation performed by the USGS in 2002. Comparison of the results validates the means and standard deviations produced by the USGS methodology, but shows that the probability distributions generated are rather different and, that the USGS distributions are not skewed to right, as expected for a natural resource. This study indicates that the unrealistic shape and width of the resulting USGS probability distributions are not caused by the analytic equations or lack of correlation between input parameters, but rather the use of narrow triangular probability distributions as input variables. Adoption of the improved methodology, along with a careful examination and revision of input probability distributions, will allow a more realistic assessment of the uncertainty surrounding potential unconventional gas resources.Item The impacts of technology on global unconventional gas supply(2009-06-02) Yanty, EviAs energy supplies from known resources are declining, the development of new energy sources is mandatory. One reasonable source is natural gas from unconventional resources. This study focus on three types of unconventional gas resources: coalbeds, tight sands, and shales. Whereas these resources are abundant, they have largely been overlooked and understudied, especially outside of North America. New technologies, including those needed to unlock unconventional gas (UCG) resources, have been acknowledged to be the most significant factor in increasing natural gas supply in the United States. This study evaluates advances in critical technology that will most likely increase supply the most. Advanced technology is one of the main drivers in increasing unconventional natural gas production, as observed in the United States, Canada, and Australia. 3D seismic, horizontal drilling, multilateral completion, water and gel based fracturing, coiled tubing rig, enhanced recovery, and produced water treatments are current important technologies critical in developing unconventional gas resources. More advanced technologies with significant impacts are expected to be available in the next decades. Fit-to-purpose technology reduces the cost to recover gas from unconventional resources. The better the unconventional gas resources are characterized, the better we can tailor specific technology to recover the gas, and less cost are needed. Analogy assumption is a good start in deciding which critical technology to be transferred to undeveloped unconventional reservoirs. If the key properties of two unconventional gas basins or formations are more or less similar, it is expected that the impact of certain technology applied in one basin or formation will resemble the impact to the other basin or formation.