Ian Palmer - Academia.edu (original) (raw)

Papers by Ian Palmer

Energy Procedia, 2013

Coal-Seq III is a 3-year public-private consortium primarily sponsored by the U.S. Department of ... more Coal-Seq III is a 3-year public-private consortium primarily sponsored by the U.S. Department of Energy (DOE) and performed by Advanced Resources International (ARI) in partnership with Southern Illinois University (SIU), Oklahoma State University (OSU), and Higgs-Palmer Technologies. The consortium has a primary objective to advance scientifically-based simulation capabilities for CO 2 storage in coalbed methane and gas shale reservoirs in the presence of multicomponent gases and other fluids in order to improve how current simulation tools model the effects of high pressure CO 2 on the integrity and swelling/shrinkage of the coal matrix and its permeability as well as proper algorithms for the adsorptive capability of wet coals. To accomplish this goal, coal samples from various U.S. basins are being used in the laboratory to study the potential existence of a change in mechanical properties for the coal (weakening/failure) under high-pressure CO 2 injection and depletion. Laboratory experiments also include the investigation of coal shrinkage (during production) and swelling (during injection) under field replicated conditions. In addition; new improved adsorption models are being developed to realistically simulate sequestration in wet coal and gas shale reservoirs. Based on the laboratory and theoretical results, three new geochemical and geo-mechanical modules will be developed. Finally, the feasibility of storing CO 2 in shale reservoirs will be studied using actual datasets, leveraging the basic science work developed by this effort. To do so, the Coal-Seq III Consortium work will calibrate the accuracy of these modules with data from large-scale field studies, such as the DOE sponsored CO 2 injection demonstration within the San Juan basin's Fruitland coal, and incorporate these modules into an advanced, coupled simulation model. The end result will be improved tools that are informed by Coal-Seq laboratory efforts and that have been tuned with field injection data. This paper will describe the efforts to date in meeting these research objectives.

SPE Production Engineering, 1990

Summary The pressure transient that spreads through the formation during and after a hydraulic fr... more Summary The pressure transient that spreads through the formation during and after a hydraulic fracture treatment pressurizes the formation and induces a certain "swelling." This swelling and the accompanying uplift at the earth's surface can be estimated with poroelastic theory. The uplift may produce a significant signal in tiltmeter devices placed at the surface. Six fracturing treatments in liquid-saturated reservoirs, all with tiltmeters to diagnose the fractures, were analyzed. In five cases, routine tiltmeter analysis postulated a horizontal fracture component (in the remaining case, a near-vertical fracture of dip 70 to 85° probably could also be interpreted by a vertical fracture with a subsidiary horizontal component). In three treatments, however, theoretical tilts calculated from the pressure transient can account for the magnitude of the tiltmeter signals, which had previously been explained by a horizontal fracture component. This result is important beca...

Proceedings of International Meeting on Petroleum Engineering, 1992

Coalbed methane is an abundant resource in the U.S.A., for example, in the San Juan Basin (50 TCF... more Coalbed methane is an abundant resource in the U.S.A., for example, in the San Juan Basin (50 TCF), and Black Warrior Basin (20 TCF). Amoco has drilled many wells in both basins in the last few years. Different completions and stimulations have been tried, and these are summarized as follows:Openhole cavity - This has worked best in areas of the San Juan Basin where reservoir pressure and permeability are high. The wells can be prolific producers (up to 12 MMCFD). The physical mechanisms involved in the completion are discussed, and these are used to try to understand the difference in gas production between cavity completions and gel fracture stimulations.Gel fracture treatments - These stimulations are conducted through perforations in coal seams, and sometimes two or more stages are used per well. High fracture conductivities are achieved by using 12/20 mesh sand to concentrations of 10 ppg, and the viscous gel should mean most of the coal seams are propped. Graduated proppant treatments (40/70 sand preceding the main 12/20sand) are often used to alleviate screen-outs. Although some gel damage to the coal formation is evident, moderate productivity increases have been achieved.Water fracture treatments Because of gel damage to the formation, fracturing treatments have been conducted using water as fracture fluid, plus 12/20 sand to concentrations of a few ppg. Although not all coal seams are expected to be propped (due to low viscosity of water), gas production is greater in general than offset wells with gel fracture treatments, and the water fractures are cheaper.Sandless water fracture treatments - Recently water fracture treatments have been performed without sand, using ball sealers to open up more seams. Although their gas production may not be as good as wells fractured with water and sand, they can be substantially cheaper. Fracture designs are summarized, and gas production is compared for the different completion/stimulation techniques. Fracture treatments in general appear to fall into two different classes: First, those in which significant fracture height growth occurs, accompanied by falling pressures (vertical fractures). The second class are pressures (vertical fractures). The second class are those which are largely confined by the coal seams, and are accompanied by steady or rising pressures, proppant-induced pressure increases, and ISIP values greater proppant-induced pressure increases, and ISIP values greater than 1 psi/ft (T-fractures). Interpretations of fracture geometry, height growth or confinement, fracturing pressure, and proppant-induced behavior, are pressure, and proppant-induced behavior, are summarized. Introduction Hydraulic fracturing of coalbeds, which is the most common form of completion/stimulation, is not fundamentally different from fracturing of conventional formations, although some adaptations have certainly been made. However, other completion/stimulation techniques such as the openhole cavity have been reintroduced recently, and when they have worked they appear to be more productive than the fracture stimulations. Our understanding of these completions/stimulations is still evolving. P. 679

Unconventional Energy Resources: Making the Unconventional Conventional: 29th Annual, 2009

SPE Western Regional Meeting, 2010

After 30 years of CBM production in the USA, and internationally more recently, general principle... more After 30 years of CBM production in the USA, and internationally more recently, general principles and decision trees have emerged to guide an operator in choosing a well completion based on permeability. If enough permeability measurements are made, well completions can be prioritized, and hybrid well completions evaluated. The benefits of horizontal and multilateral wells are made clear. Low permeability is a serious challenge for CBM ventures, and further success will entail finding regions of enhanced permeability, utilizing horizontal wells, and "creating" permeability by new-paradigm methods. Perm-based guidelines for CBM well completions are given, which include permeability bands and benchmarks. Industry success has led to two benchmarks for evaluating ahead of full-field development (1) commercial success from reservoir parameters, and (2) effectiveness of well completions. The perm-based guidelines are simple and practical, and should benefit any CBM completions ...

SPE Gas Technology Symposium, 1998

This case history paper describes a technique that minimizes the creation of multiple fractures i... more This case history paper describes a technique that minimizes the creation of multiple fractures in deep coal seams during hydraulic fracturing operations. The technique enabled the operator and the service company to perform 24 nitrogen foam-fluid fracturing treatments in 33 days in the Upper Silesian basin (Poland). The creation of multiple fractures is a phenomenon often encountered during fracturing operations in coal seams and is the most probable cause of early screenouts. During this fracturing campaign, early screenouts were observed at sand concentrations less than 3 lb/gal. These screenouts were attributed to a lack of fracture width caused by the presence of multiple fractures, including possible horizontal fracture components or tortuosity. The operator and the service company developed a technique that involves pumping a small volume of highly viscous crosslinked gel before the main fracturing treatment. This technique prevented early screenouts and allowed the higher sa...

SPE Western North American and Rocky Mountain Joint Meeting, 2014

With depletion of coalbed methane (CBM) wells in the San Juan Basin, permeability rises by 10 to ... more With depletion of coalbed methane (CBM) wells in the San Juan Basin, permeability rises by 10 to 100 times. Similar permeability increases are found in other CBM basins around the world. Models previously advanced to explain this behavior combine a compaction mechanism (which closes cleats) with matrix shrinkage (which opens cleats). In this paper, the original model (Palmer-Mansoori model) is extended to include the transversely isotropic elastic response found in vertically cleated coals. This new version of the model has been calibrated by laboratory measurements on San Juan Basin coal loaded under uniaxial-strain conditions to simulate reservoir depletion. The result is a predictive model characterized by two measured Young's moduli and three measured Poisson's ratios. To our knowledge, a rigorous geomechanical analysis of anisotropic coal has not before been incorporated into efforts to match large permeability increases observed in the field. We have been able to match...

SPE Asia Pacific Oil and Gas Conference and Exhibition, 2011

We discuss detailed well history matches, from the San Juan basin, of coalbed methane (CBM) gas r... more We discuss detailed well history matches, from the San Juan basin, of coalbed methane (CBM) gas rates, water rates, and pressures. In the sweetspot (fairway) the matching includes permeability that increases strongly with depletion, and is assumed to be exponential, as indicated by independent well tests spaced over time. The permeability increases are well matched by the Palmer-Mansoori (P-M) model. We present statistics of permeability matching to field results by the P-M model in the fairway. First, initial cleat porosities are 0.05–0.17% and consistent with porosities derived from observed water rates. Large permeability increases are not consistent with large cleat porosities. Second, the permeability increase ratio, defined by the maximum permeability reached over the permeability at initial reservoir pressure, varies from 16–170. Third, the matrix shrinkage parameters agree with a recent lab measurement. Fourth, cleat-volume compressibility mostly increases with depletion, wh...

SPE Annual Technical Conference and Exhibition, 2005

We provide a summary of coal failure during the life of a typical coalbed methane (CBM) well, and... more We provide a summary of coal failure during the life of a typical coalbed methane (CBM) well, and some consequences for the CBM industry. Because coals are weak in general, these consequences are often important, and can have a significant impact on drilling, completion, and production of CBM wells. Failure during drilling: horizontal wells are the preferred completion in the Arkoma basin, for instance. Drilling horizontal wells is sometimes hindered by hole collapse, especially when drilling underbalanced, or drilling through a depleted coal. We demonstrate the relative importance of this by comparing drilling stability in coals of various ranks and depths. Failure during hydraulic fracturing: in weak coals the increased pore pressure around a fracture can cause shear failure. The likelihood of shear failure is charted against coal rank, for given in situ stress, and fracturing pressure. When coal fails in shear, coal fines are produced in the reservoir, as has been demonstrated in...

Journal of Petroleum Technology, 1991

Summary Fracture stimulation is commonly used for coal degasification at the Black Warrior basin ... more Summary Fracture stimulation is commonly used for coal degasification at the Black Warrior basin in Alabama. To understand coalbed fracturing better, Well AM-1 inthe Oak Grove field was completed openhole in the section bracketing the Black Creek coals. Special diagnostics used on this project included variousinjection tests, static-line pressure measurements, and a downhole pressuremeasurements, and a downhole television camera. The television camera observedfractures during injection tests and after the propped fracture treatment. Theauthors believe these are the first successful downhole television pictures ofpropped fractures in coalbeds. propped fractures in coalbeds. Resofts werecompared with predictions of hydraulic fracture simulators. This is a valuableway of "calibrating" hydraulic fracture models for improveddesign/optimization. Introduction In March 1989, special diagnostics were used to gather information on thenature of hydraulic fractures in coalbeds of the ...

SPE Annual Technical Conference and Exhibition, 2008

It is well known that absolute permeability changes occur in coalbed methane (CBM) reservoirs dur... more It is well known that absolute permeability changes occur in coalbed methane (CBM) reservoirs during primary depletion or enhanced recovery/CO2 sequestration operations. Sorption-induced strain in CBM reservoirs, also known as matrix-shrinkage or -swelling, may dominate permeability changes at low pressures, as is the case for CBM wells undergoing primary depletion in the Fruitland Coal fairway of the San Juan Basin. Several analytical models have been developed to predict changes in coal permeability as a function of stress and sorption. Most models, however, utilize an empirical method for estimating sorption-induced strain. Recently, a theoretical model for sorption-induced strain was developed and applied to single-component adsorption/strain experimental data. The new model was developed from basic thermodynamic principles and is more predictive than the empirically-based approaches. In this paper, the theoretical model is expanded to incorporate multi-component adsorption mode...

SPE Production & Operations, 2013

Summary Microseismic measurements provide qualitative information about the location of a fractur... more Summary Microseismic measurements provide qualitative information about the location of a fracture stimulation. However, there is also quantitative information to consider, a fact that has largely been neglected. We have developed a geomechanical model to predict the extent of shear failure during fracture stimulation of a well. The model identifies different types of failures, tensile and shear, which will occur on natural fractures or vertical planes of weakness. It is a “screening model,” meaning it takes a global perspective where point-by-point details of natural fracture distribution, fluid leakoff, and failure prediction are not emphasized. By matching the model to the extent of the microseismic cloud of shear failure, we obtain an injection permeability and porosity which characterize the volume of the microseismic cloud, which we assume to be a quasi-uniform fracture network with a system permeability enhancement. The model can be applied to any formation in which the micro...

Proceedings of International Meeting on Petroleum Engineering, 1995

Amoco is producing coalbed methane from several hundred wells in both San Juan and Warrior basins... more Amoco is producing coalbed methane from several hundred wells in both San Juan and Warrior basins. These wells were completed/stimulated in one of two ways : (1) open hole cavity completions, (2) hydraulic fracture stimulations through perforations in casing. Cavity operations are described, and new data from several cavity completions is presented and analyzed. The latest geomechanics modeling of the formation of cavities in coalbeds is presented. The model allows the growth of a cavity as tensile failure occurs, and computes increases in permeability in a stress-relief zone that extends tens of feet from the well. Critical parameters are given for the success of cavity completions. A pulse interference analysis is discussed : as well as interwell permeability, this can provide information on stress-dependent permeability. Finally, some wells which were originally cavitated did not perform up to expectation, and have been recavitated with remarkable success - these are also examined. Amoco has tried several different kinds of hydraulic fracturing treatments. Results of comparisons between foam fracture, slick water fracture, and gel fracture treatments are presented. Statistical comparisons are given for regions outside of the fairway zone in the San Juan Basin. In the Warrior Basin, water fracture treatments with and without sand have been compared. Lastly, foamed water cleanouts, without sand, have been deployed, and their success is reviewed.

SPE International Symposium and Exhibition on Formation Damage Control, 2008

A detailed sand prediction has been made for three wells at Chevron's West Seno field based o... more A detailed sand prediction has been made for three wells at Chevron's West Seno field based on logs/lab data and the results have been calibrated with production data. Both maximum allowable drawdown and depletion increase with depth. Additionally, oriented perforations offer an improvement to perforation stability against sanding: the maximum allowable drawdowns and depletions are increased for all sands. Finally, an analysis is presented on the economics and trade-offs of vertically-oriented perforating (with possibly managed sand production) versus frac-packing. Sand onset prediction agrees fairly well with the observed drawdown/depletion for horizontal perforations. This benchmarking appears to support the validity of the shear-failure model. This is important because the model, while fairly simple, has many different inputs, including depth profiles for unconfined compressive strength (UCS) and in-situ stresses, which involve sophisticated prediction techniques themselves. ...

SPE Annual Technical Conference and Exhibition, 2003

Sand prediction at BP has been developed by dividing it into three parts:onset,transient sanding,... more Sand prediction at BP has been developed by dividing it into three parts:onset,transient sanding,steady-state sanding. For example, as drawdown is increased in a well in a sand-prone formation, significant sanding begins at some point (the onset), and this is followed by a transient sand burst, which may last hours or days or months. The sanding eventually declines to a background level (steady-state), in the range 1–100 pptb. We have made recent step-changes in (2) and (3), and we now have a tool that can predict sanding onset, and volumes during any stage of a well's production history, or even injection history. The onset of sanding is predicted using a stress-based model. This model is conservative, based on a benchmarking study of field applications. One application predicts sanding in water injectors during shut-in, and recommends not using sand control. Another application explains delayed sanding in an HPHT gas reservoir, in terms of restraining forces due to capillary c...

SPE Reservoir Evaluation & Engineering, 1998

This paper (SPE 52607) was revised for publication from paper SPE 36737, first presented at the 1... more This paper (SPE 52607) was revised for publication from paper SPE 36737, first presented at the 1996 SPE Annual Technical Conference & Exhibition, Denver, 6-9 October. Original manuscript received for review 25 October 1996. Revised manuscript received 17 August 1998. Paper peer approved 1 September 1998. Summary In naturally fractured formations such as coal, permeability is sensitive to changes in stress or pore pressure (i.e., changes in effective stress). This paper presents a new theoretical model for calculating pore volume (PV) compressibility and permeability in coals as a function of effective stress and matrix shrinkage, by means of a single equation. The equation is appropriate for uniaxial strain conditions, as expected in a reservoir. The model predicts how permeability changes as pressure is decreased (i.e., drawdown). PV compressibility is derived in this theory from fundamental reservoir parameters. It is not constant, as often assumed. PV compressibility is high in ...

SPE Journal, 2010

Summary It is well known that absolute permeability changes occur in coalbed methane (CBM) reserv... more Summary It is well known that absolute permeability changes occur in coalbed methane (CBM) reservoirs during primary depletion or enhanced recovery/CO2 sequestration operations. Sorption-induced strain in CBM reservoirs, also known as matrix shrinkage or swelling, may dominate permeability changes at low pressures, as is the case for CBM wells undergoing primary depletion in the Fruitland coal fairway of the San Juan basin. Several analytical models have been developed to predict changes in coal permeability as a function of stress and sorption. Most models, however, utilize an empirical method for estimating sorption-induced strain. Recently, a theoretical model for sorption-induced strain was developed and applied to single-component adsorption/strain experimental data. The new model was developed from basic thermodynamic principles and is more predictive than the empirically based approaches. In this paper, the theoretical model is expanded to incorporate multicomponent adsorptio...