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Collaborating Authors
Hydraulic Fracturing
Abstract The equations describing the transient flow of a fluid with low compresibility through a series of connected porous media with contrasting geometries and/or properties were coupled into one single vector equation. That equation describes pressure and flow velocity at any point in that composite medium and in the Laplace domain. Numerical symmetric transforms are used to obtain solutions in terms of time. A distinction is made between actual composite geometries in which flow is delimited by actual boundaries in different configurations; and virtual composite geometries, in which flow geometries are observed in pressure plots though no physical boundaries guide the flow. The formulation was validated through applications to cases presenting composite geometry flow patterns that have been analyzed previously through approaches different from the one presented. P. 9
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Pressure transient analysis (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Drillstem/well testing (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring (1.00)
Abstract Breaking a paradigm is to try to solve any situation with a different point of view and different sources. Everyone believes that for drilling a gas well, it is obviously necessary to use only drill pipe. Pemex Exploration & Production (PEP) is giving a tremendous change in this direction in the North of Mexico, in the area of Burgos Basin, Reynosa, Tamaulipas. PEP had successfully drilled more than 40 gas wells using upset tubing with WedgeThread Technology to drill the last section of the well, using the slim hole design and applying the "Tubingless Technique" for completion. This has given PEP the opportunity to save 30 to 40% of total cost of each gas well. The conventional drilling programs used to be 17-1/2 in, 12-1/4 in. and 8-1/2 in. bit diameters and 13-3/8 in., 9-5/8 in. and 7 in. casing diameters respectively. This normally requires a 4 1/2 in. drill pipe for drilling the three sections, because the capacity of this pipe (torsion, tension and hydraulics geometry). Finally, the completion was performed with a 2-7/8 in. tubing with a permanent packer on top of the production zone. The new drilling program requires 12-1/4 in., 8-1/2 in. and 5-7/8 in., bit diameters and 9 5/8 in., 7 in. and 3-1/2 in. casing diameters respectively. The 3-1/2 in. tubing has an integral connection on internal-external upset pipe with the Wedge Thread Technology to drill the last section and then it is cemented as a production casing (tubingless technique). Also this tubing has an amazing application to drill because its torsion, tension, bending and compression strengths. Therefore, this 3-1/2 in. tubing has a triple application: as a drill pipe, production casing and tubing. P. 465
- North America > Mexico > Tamaulipas > Burgos Basin (0.99)
- North America > Mexico > Nuevo Leon > Burgos Basin (0.99)
- North America > Mexico > Coahuila > Burgos Basin (0.99)
- Well Drilling > Drilling Operations (1.00)
- Well Drilling > Drilling Fluids and Materials (1.00)
- Well Drilling > Drill Bits (1.00)
- (3 more...)
Gulf of Mexico Frac-and-Pack Treatments Using a New Fracturing Fluid System
Powell, R.J. (Halliburton Energy Services Inc.) | McCabe, M.A. (Halliburton Energy Services Inc.) | Slabaugh, B.F. (Halliburton Energy Services Inc.) | Terracina, J.M. (Halliburton Energy Services Inc.) | McPike, T. (Shell E & P Technology Co.)
This paper was prepared for presentation at the 1998 International Petroleum Conference and Exhibition of Mexico held in Villahermosa, Mexico, 3-5 March 1998. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s).
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Well Completion > Sand Control > Frac and pack (0.77)
Controlled Viscosity Reduction and Increased Fracture Conductivity Using a High-Temperature Breaker System
Dusterhoft, R. (Halliburton Energy Services Inc.) | Parker, M (Halliburton Energy Services Inc.) | McCabe, M (Halliburton Energy Services Inc.) | Schubarth, S. (Halliburton Energy Services Inc.)
Abstract High-temperature fracturing-fluid breaker systems have been used in fracturing operations for the past several years. The advantage of using these systems has been improved fracture conductivity, but there has been an increased risk of poor proppant placement and premature screenouts resulting from early viscosity reductions as the fluid is exposed to high temperatures. In many cases, this problem could only be avoided by adding breaker to the final portion of the proppant stages, essentially improving the fracture conductivity in the near wellbore region without enhancing the conductivity of most of the proppant pack. This paper highlights innovative research for developing high-temperature breakers that work synergistically with gel stabilizers to maintain excellent gel viscosity. This viscosity allows sufficient time to place the treatment while still providing a more complete break and improved fracture conductivity. Laboratory testing has shown that this high-temperature breaker system can be used effectively at temperatures as high as 350 F without sacrificing early-time fluid viscosity or proppant placement, while still providing dramatic improvements in fracture conductivity. Field production has been analyzed and shows the combined benefits of improved proppant placement and increased fracture conductivities obtained with the application of this technology. P. 409
Improved Selection of Candidates for Stimulation Treatment in the Wilcox Play in the South Texas/Mexico Border Area
Boonen, P. (Halliburton Energy Services) | Byrd, A.C. (Halliburton Energy Services) | Frisch, G. (Halliburton Energy Services) | Kessler, C. (Halliburton Energy Services) | Kubelka, G. (KCS Resources Inc.) | Nixon, Mark (Consultant)
Abstract A particular South Texas gas field has suffered severe production decline in the last two years. The wells were completed in the Wilcox formation, which extends from the Burgos Basin in Mexico through Texas into Louisiana. The object was to identify and treat potential producing zones in all existing wells to increase production. Hydraulic fracturing is the preferred stimulation technique in these formations. Typically multiple zones are fractured in each of the wells. The stimulation treatments are designed with the aid of 3D hydraulic fracture models. Wireline logs provide the most comprehensive and continuous input parameters in such modeling for borehole stress profile, permeability index, elastic moduli, lithology, porosity and fluid saturation's. Existing open-hole wireline logging data were reprocessed using a new technique which provides all the available logging data in a format suitable for direct input in 3D hydraulic fracture models. An automatic zoning technique divides the data into consistent intervals based on stress contrast. The representative design parameters are then computed for each zone. The outputs are a blocked stress profile and a set of zoned fracture design parameters. This new technique was used to evaluate all the stimulation candidates in the field. One well was bypassed for treatment altogether, saving ﹩500,000 to ﹩700,000 on a stimulation that would have had a marginal result at best. In another well, the log was used in combination with a Fluid Efficiency Test (FET) and a Step Rate Test to show essentially no leak-off, and hence very low permeability in one zone. This lower sand was skipped, and upper zones were fractured to increase gas production from 550 MMCF/D to 1,300 MMCF/D. P. 399
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.49)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
Abstract Designing gas injection projects in naturally fractured reservoirs requires special considerations which, in turn, relies on knowledge of the fracture network. Characterization of the fracture network involves delineation of important physical characteristics, such as fracture spacing, fracture orientation, fracture conductivity (of both natural and hydraulically induced fractures). Of equal significance is understanding the transfer mechanisms between oil and gas in the rock matrix and injected water and gas present in the fracture network. Integration of fracture characterization with results obtained during experimental investigation of transfer mechanisms is a key step for history matching and predicting reservoir response to water or gas injection. This paper describes the steps taken in two important areas of 1) fracture characterization and 2) fluid exchange from fracture to matrix as a precursor for design of a 10 acre CO2 pilot in the naturally fractured Spraberry Trend Area. Fracture and matrix characterization are based on oriented vertical and horizontal core taken from Upper Spraberry reservoirs. Fluid exchange mechanisms are investigated in reservoir plugs and whole core at reservoir temperatures and pressures. Results of imbibition/wettability and CO2 gravity drainage experiments are presented. History matching Spraberry waterflood performance and predicting performance. under CO2 injection is presented based on integration of reservoir characterization and laboratory experimentation. P. 325
- North America > United States > Texas > Midland County (1.00)
- North America > United States > Texas > Martin County (1.00)
- North America > United States > Texas > Howard County (1.00)
- North America > United States > Texas > Dawson County (1.00)
- Geology > Geological Subdiscipline > Geomechanics (0.68)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.31)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (24 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Faults and fracture characterization (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
This paper was prepared for presentation at the International Petroleum Conference and Exhibition of Mexico held in Villahermosa, 3-5 March 1998.
- North America > United States > Texas (1.00)
- North America > Mexico > Nuevo León (1.00)
- Geology > Structural Geology > Fault (0.94)
- Geology > Geological Subdiscipline (0.69)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.47)
- North America > United States > Texas > Sabinas - Rio Grande Basin > McAllen Ranch Field > Vicksburg Formation (0.99)
- North America > United States > Texas > Sabinas - Rio Grande Basin > Bob West Field (0.99)
- North America > United States > Texas > East Gulf Coast Tertiary Basin > Wilcox Formation (0.99)
- (8 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring (1.00)
- (8 more...)
This paper was prepared for presentation at the SPE International Petroleum Conference and Exhibition of Mexico held in Villahermosa, Mexico, 3-5 March 1998.
- North America > United States > Texas (0.46)
- North America > Mexico > Tabasco > Villahermosa (0.24)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- (7 more...)
Abstract Surface mapping can be used to evaluate reservoirs where fractures influence the flow of fluids. Fracture zones mapped at the surface appear to reflect structures at depth that act as impermeable barriers to flow across the zone and as conduits for fluid flow along the zone. Airphotos were used to evaluate a fractured carbonate reservoir at Cottonwood Creek field, Bighorn basin, Wyoming. Cottonwood Creek produces from a stratigraphic trap in the Permian Phosphoria Formation at depths from 1538-3077 meters. Surface lineaments were interpreted on color-infrared stereo airphotos (1:58,000) and then digitized. Contour maps were generated of total surface fracture density and fracture density within various trends. These maps were compared to subsurface data to determine if they had any relationship to reservoir properties. The principal (northwest) fracture set is unrelated to production. A map of northeast fracture density shows intense fracturing that corresponds to zones of increased total porosity-feet and high cumulative production. Enhanced recovery programs must account for these fracture zones. Introduction The purpose of this work is to demonstrate that surface mapping can help plan and evaluate enhanced production programs where there is a likelihood of fractures controlling the flow of subsurface fluids. In fractured reservoirs it is common to have premature breakthroughs in waterfloods or gas floods as a result of enhanced permeability and porosity in the fracture zone. Fractures can behave as impermeable barriers to flow by preventing the movement of reservoir fluids across the fracture zone and by channeling the fluids along the zone parallel to the trend of the fractures. The Cottonwood Creek field in the Bighorn Basin, Wyoming, provides an example of the use of airphotos to map surface fractures that are related to fracturing in the producing reservoir (Fig. 1). The field is a stratigraphic trap in the west-dipping Permian Phosphoria Formation at depths between 1538 and 3077 m. Oil is trapped by the updip pinchout of a porous dolomite facies as it grades into an impermeable shale-anhydrite facies. The Phosphoria reservoir is up to 40 m thick within the field, and porosity averages between 8 and 10%. Average permeability is 1 md. Porosities as high as 20%, and permeabilities as high as 800 md have been reported. These variations in porosity and permeability have been attributed to factors such as the transition from a silty dolomite to fine-grained dolomite, plugging of porosity by diagenetic calcite and anhydrite, fenestral (vuggy) porosity, and fracturing. Engineers first suspected a fractured reservoir when a gas injection program resulted in a rapid movement of gas to producing wells and oil production declined. A water injection program begun the following year had similar results. Jointing in the reservoir was suspected as the cause of the premature breakthrough along the probable fracture zones. Procedure Lineaments were mapped on color-infrared stereo airphotos at a scale of 1:58,000 (National High Altitude Program) over an area covering 14 townships (1300 km2). The lineaments were then digitized and evaluated using an Amoco fracture analysis program. The density of fractures was contoured in line-kilometers of fractures for each 10 km2 grid cell. Ideally, fracture density mapping is performed in an area of little or no dips and with uniform surface cover in order to minimize the effect of changes in lithology. There was some concern that some units in the Cottonwood Creek area would have a higher density of fractures because of their mechanical properties (e.g., sandstones are more brittle than shales, thus might be more fractured). A comparison of the fracture density map with the geologic map of the area showed that this is not the case here. Since all of the surface units have the same general dip (4-10 to the southwest) and roughly the same geomorphic expression, fracture density differences between lithologies are minimized. Maps of the density of all fractures and of fractures within specific trends were compared to production data to determine whether there was a correlation. P. 25
- North America > United States > Wyoming > Washakie County (1.00)
- North America > United States > Texas > DeWitt County (0.96)
- North America > United States > Oklahoma > Carter County (0.96)
- Geology > Structural Geology > Tectonics (1.00)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock > Dolomite (0.66)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.45)
- (2 more...)
- North America > United States > Wyoming > Bighorn Basin > Phosphoria Formation (0.99)
- North America > United States > Wyoming > Bighorn Basin > Cottonwood Creek Field > Phosphoria Formation (0.99)
- North America > United States > Montana > Bighorn Basin (0.99)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery (1.00)
Abstract The study of fracturing in carbonate formations has become a critical factor for the exploitation policies for the main oil and gas producing reservoirs in Mexico, since a great percentage of hydrocarbons production is associated with this kind of reservoirs. In this paper a methodology that integrates diverse sources of information at different spatial scales is proposed, the range of spatial scales goes from the microscopic level study of thin section of rocks and cores to the megascopic level where fracturing is determined with seismic information. To define reservoirs fracturing it has been utilized information derived from cuttings samples, cores, well logging, wellbore images, well testing and seismic interpretations. Given that the fractures are not isolated phenomena in nature, the studies herein described, target to know their origin, in this way, fractures and their spatial relations are identified with the purpose of defining fracture system, principal stresses and their association with major tectonic features such as folds and faults; letting know the fracturing pattern and its association with the geologic model of the area. Fracture parameters are estimated by means of core analysis and well log information using indices derived mainly from resistivity and porosity logs, on the other hand, fracture orientation is determined from dipmeter information, wellbore images and its correlation with cores. The application of this method and its results in two fields of Mexico are shown, these results allowed to establish models at well and reservoir levels. Also from these it was possible to estimate preferential fracture orientations in areas not yet drilled, which is of great importance for the optimum field development. Introduction A big part of Mexico's oil reserves come from reservoirs located in the country's SE region, in these fields naturally fractured carbonate reservoirs abound, and their geological ages range from Earlier Paleocene to Late Jurassic, the units found there, show sequences of partially dolomitized limestones with low content of clays. Porosity varies from 3 to 23%, and a great part of it is due to fractures and vugs, an example of this type of formations is given in figure 1. The estimated permeabilities for these units are greater than 2 darcies which explains the high productivities of some wells completed in these units, some wells reached productions greater than 30,000 bpd. Fractures are discontinuities due to a rock's lost cohesion, they also represent a volume that can be occupied by fluids and that can serve as preferential flow paths. There are many models to explain the origin of fractures resulting from underground stresses, in general fractures can be classified in 1, 2, 3.–Gravitational: due to compaction of large volumes of rock and decompaction of clays. –Tectonic: due to folding, faulting and diapirism. P. 17
- North America > Mexico (1.00)
- Europe > Norway > Norwegian Sea (0.24)
- Geology > Geological Subdiscipline (0.96)
- Geology > Structural Geology > Tectonics (0.87)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.34)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Interpretation (0.35)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Carbonate reservoirs (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)