bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-frequency LWD Acoustic Tool for Shear Slowness Measurement.
Authors: Andonof Luis J. , Buster Derek , Eiane Tor , Petpisit Kiattisak
Published: September 2008

This paper presents some case histories involving multi-frequency quadrupole acoustic measurement to obtain the formation shear slowness under varying conditions. Quadrupole modes in high frequencies for fast formations acquired in parallel with low frequencies for slow formations are processed such that the final result is that the combination of both responses yield the shear slowness across the range encountered. These conditions range from large shallow boreholes with unconsolidated formations to consolidated formations where the shear velocity is faster or close to mud compressional velocity.

As is well known in the industry, the monopole mode allows the measurement of shear slowness in fast formations. However, for slow formations this refracted shear does not exist which requires other means to be employed. The application of the dipole measurement which is used in wireline encounters problems in the Logging While Drilling (LWD) environment. These problems are due to the presence of the collar which greatly influences the flexural mode in the formation along with the additional signal caused by the collar flexural wave1.

Cases when the shear slowness lies in the range of the fluid slowness, a special treatment needs to be considered. The fact that one frequency (high or low) is unable to accurately respond above and below this threshold emphasizes the advantage and need for having multi-frequency LWD acoustic data to accomodate the demands of the environment. Also the challenging case where the shear slowness is in the same range as the mud compressional slowness will be discussed. All these results point to the importance of the use of a multi-frequency LWD acoustic tool for shear measurements. Some quality control considerations such as the rate of penetration (ROP) need to be taken into account in order to have a successful job.
Successful Field Application in Continuous DTS Monitoring Under Harsh Environment of SAGD Wells Using New Optical-Fiber Technology: Case Study From Canada
Authors: Kaura Jiten , Sierra Jose
Published: September 2008

The use of optical fibers in the oil and gas industry is becoming more viable for several applications, particularly in permanent reservoir monitoring, such as distributed temperature sensing (DTS) and optical pressure transducers. However, poor long-term performance of fibers, especially at elevated temperatures, is still an issue yet to be fully resolved. This problem is critically important in steam assisted gravity drainage (SAGD) applications, where wells operate in extreme conditions of high temperatures, often exceeding 250°C, as well as in high pressures within a hydrogen-rich environment.

Optical fiber performance is seriously affected by many factors, including: Hydrogen ingressionThermal resistance of the materialsMechanical resistance of the fiber

Exposure of optical fibers to hydrogen changes the performance of the fibers through what is referred to in the industry as "hydrogen aging" or "hydrogen darkening." Hydrogen darkening is increased absorption or light loss due to various chemical species in the glass fiber resulting from the presence of hydrogen.
Dehy 20 Water Filtration Plant—A Closed Loop Water Treating Facility
Authors: Grishaber E. L.
Published: September 2008

A Southern California oil producer needed to expand its light oil waterflood. An existing oil treating plant was expanded to include a new state-of-the-art water plant to recycle all produced water associated with light oil production for use in the existing waterflood. The new 350,000–barrel-per-day water plant was designed to treat the produced water to remove suspended solids and oil to a specification that equaled or exceeded the existing waterflood aquifer source. In addition, the plant had to minimize waste while maximizing treated water output and be built for a 40-year life. The plant addition was designed and constructed using a unique combination of water de-oiling, desanding, and filtration equipment together with centrifuges and gas flotation equipment similar to equipment used in municipal wastewater treatment plants. All wastes such as filter backwash are processed and reused.

The water plant is now operational, performing at or above expectations. It treats and recycles more than 340,000 barrels of water per day for use in the field's waterflood project. This recycling has largely displaced the existing waterflood source supply system (saving power and well maintenance and replacement costs) and reduced produced water disposal well injection costs resulting from much improved water quality. The new plant has met its goal of providing a high-quality water source for waterflood with typically less than 2 milligrams per liter of solids, oil, and grease.
Friction-Based Thermal Desorption Technology: Kashagan Development Project Meets Environmental Compliance in Drill-Cuttings Treatment and Disposal
Authors: Murray A. J. , Kapila M. , Ferrari G. , Degouy D. , Espagne B. J. , Handgraaf P.
Published: September 2008

Friction-based thermal desorption, with temperatures between 260 and 300°C, allows the oil and water phases to be volatilized and subsequently condensed and recovered, leaving dried and cleaned solids that can be disposed. Friction-based thermal desorption reduces the residual oil on the cuttings while recovering oil and other materials for reuse.

This paper presents the novel friction-based thermal desorption system currently deployed in the relatively hostile and remote Koshken area, located on the steppe escarpment above the eastern shore of the Caspian Sea, Kazakhstan. This project is expected to produce 50,000 tonnes of oil-based drilling fluid or "mud" (OBM) drill cuttings annually, which must be treated to below 1% TPH oil before disposal. Any treatment technology utilized in this environment faces operational and logistical challenges, including the severe climate and the need to transport the drill cuttings from an offshore facility to an onshore centralized location. Improvements in friction-based thermal desorption technology were developed specifically for the Koshkani project to ensure health, safety and environmental (HSE) compliance and allow a best-in-class system to operate in this harsh environment.

In this paper, the authors describe the three-year development process, from initial design and equipment construction through installation, commissioning and operation. Analytical data presented includes analysis of discharged material, recovered base oil and air emission analysis. A comparison is made between the application of thermal desorption technology and alternative technologies used in similar projects.

Friction-based thermal desorption met increasingly high performance expectations and technology advancements allowing them to be achieved with assured HSE performance. Given the environmental performance that the Kashagan project required, this technology has proven to be the simplest, easiest and most effective system to implement in this environment with assured success.
Testing of New PDC Cutter Edge Geometry Doubles Penetration Rate and Reduces Torque
Authors: Barton Steven , Setlur Deepthi , Clegg John
Published: September 2008

A new edge preparation of Polycrystalline Diamond Compact (PDC) cutters has been developed to target applications where either weight or torque is limited. This paper describes the geometry, which differs considerably from existing thermostable product.

Initial testing at atmospheric conditions in a drilling laboratory shows a 30% reduction in torque and a 100% increase in penetration rate when compared to conventional cutter geometry. Secondary testing was conducted with drill bit designs at a non-commercial test facility. In this controlled environment, designs with new cutter edge geometry were compared directly to those with conventional cutters. By using the same drill bit cutting structure and parameters, any difference in torque and penetration rate was solely dependent upon the cutter geometry. Additionally, to quantify any effects caused by torsional or lateral vibration, a downhole dynamics recorder was used to gather data at a high frequency sample rate.

Performance studies are presented for a variety of applications from around the world but focusing on applications within the US Rockies. They compare direct offset runs against conventional geometry cutter designs. Results demonstrate that the new geometry delivers footage and ROP equal or greater than the best field offsets.

The increased penetration rate and reduced torque provided by this geometry result from more efficient failure of the rock. This provides reduced Mechanical Specific Energy and improved drilling efficiency, thus reducing drilling costs for the operator. This is a significant step change in PDC cutter technology, dramatically increasing fixed cutter drill bit performance.
Sampling and Characterization of Rocks and Fluids for Heavy Oil Reservoir Management
Authors: Smith C. K. , Wang F. H.
Published: September 2008

Heavy oil resources have become a major asset base in the portfolio of many energy companies. Representative sampling and characterization of rock and fluids are essential for efficient and economical development of heavy oil reservoirs. This paper describes the challenges inherent in fluids and rock sampling, PVT and viscosity modeling, and fluid flow property measurements for heavy oil reservoirs.

The key elements in obtaining representative bottom-hole fluid samples from an extra-heavy oil reservoir are described in this paper with examples. Special laboratory techniques are presented for obtaining equilibrium PVT and viscosity data on heavy oil samples. A compositional PVT model that captures the unconventional phase behavior and a viscosity model that quantifies the variations of viscosity with pressure, temperature, and GOR are also presented. Customized equipment and special techniques were employed to measure high-quality relative permeability data and to accurately determine the endpoint saturations such as critical gas saturation, remaining oil saturation, and the corresponding relative permeability. Examples of successful measurements of reservoir conditions steady-sate water-oil relative permeability are presented along with the unique equipment and techniques.

This paper highlights a systematic approach for rock and fluid characterization of heavy oil reservoirs and identifies new technologies that have lead to its successful application.
Use of Multiple-Response Optimization to Assist Reservoir Simulation Probabilistic Forecasting and History Matching
Authors: Osterloh W. Terry
Published: September 2008

This paper describes a straightforward, robust, and easily managed method for assisting reservoir simulation probabilistic forecasting, probabilistic history matching, and process optimization. The method, which is widely used in numerous other engineering fields, is based on design of experiment, Gaussian process modeling (kriging), and multiple response optimization. The method enables a new perspective on probabilistic green-field forecasting - creating a simulation model in which the probability numbers of multiple responses are at the same level (p-number alignment). The method also provides a probabilistic framework for history matching and forecasts made with the matched model. Example applications of p–number alignment and probabilistic history matching are presented for primary production and steamflood EOR pilots.

Highlights of the new method include the following: 1) multiple responses (even those with different units) can be aligned or matched, 2) responses can be weighted to focus the alignment or match on preferred responses, 3) ad-hoc, manual, or trial-and-error adjustments of simulation inputs is largely eliminated, 4) the method can be used with any simulation code, and 5) the method is extensively automated, with all key steps integrated into one commercially-available statistics package.
Pilot Scale Test of a Produced Water-Treatment System for Initial Removal of Organic Compounds
Authors: Kwon Soondong , Sullivan E. J. , Katz Lynn , Kinney Kerry , Bowman Rob
Published: September 2008

A pilot-scale test to remove polar and non-polar organics from produced water was performed at a disposal facility in Farmington NM. We used surfactant-modified zeolite (SMZ) adsorbent beds and a membrane bioreactor (MBR) in combination to reduce the organic carbon content of produced water prior to reverse osmosis (RO). Reduction of total influent organic carbon (TOC) to 5 mg/L or less is desirable for efficient RO system operation.

Most water disposed at the facility is from coal-bed gas production, with oil production waters intermixed. Up to 20 gal/d of produced water was cycled through two SMZ adsorbent units to remove volatile organic compounds (BTEX, acetone) and semivolatile organic compounds (e.g., napthalene). Output water from the SMZ units was sent to the MBR for removal of the organic acid component of TOC. Removal of inorganic (Mn and Fe oxide) particulates by the SMZ system was observed. The SMZ columns removed up to 40% of the influent TOC (600 mg/L). BTEX concentrations were reduced from the initial input of 70 mg/L to 5 mg/L by the SMZ and to an average of 2 mg/L after the MBR.

Removal rates of acetate (input 120-170 mg/L) and TOC (input up to 45 mg/L) were up to 100% and 92%, respectively. The water pH rose from 8.5 to 8.8 following organic acid removal in the MBR; this relatively high pH was likely responsible for observed scaling of the MBR internal membrane. Additional laboratory studies showed the scaling can be reduced by metered addition of acid to reduce the pH. Significantly, organic removal in the MBR was accomplished with a very low biomass concentration of 1 g/L throughout the field trial.

An earlier engineering evaluation shows produced water treatment by the SMZ/MBR/RO system would cost from $0.13 to $0.20 per bbl at up to 40 gpm. Current estimated disposal costs for produced water are $1.75 to $4.91 per bbl when transportation costs are included, with even higher rates in some regions. Our results suggest that treatment by an SMZ/MBR/RO system may be a feasible alternative to current methods for produced water treatment and disposal.
Effect of Brine in Hydrate Anti-Agglomeration
Authors: York J. D. , Firoozabadi A.
Published: September 2008

Due to availability, as well as economical and environmental considerations, natural gas is projected to be the premium fuel of the 21st century. Natural gas production poses risk of flow-line hydrate blockage from co-produced water and hydrate-forming species. Common industry practice is the use of large doses of thermodynamic inhibitors such as alcohols; aside from undesirable environmental consequences, sufficient quantities of such thermodynamic inhibitors induces salt precipitation from co-produced water. Thermodynamic inhibitors affect bulk phase properties and inhibit hydrate formation. An alternative is changing interface properties by polymers and surfactants, effective at 3 to 0.5 % (or less) by weight of co-produced water. One group of low dosage hydrate inhibitors (LDHI) are kinetic inhibitors, which affect nucleation rate and growth. A second group of LDHI are anti-agglomerants, which prevent agglomeration of small hydrate crystallites. Despite great potential, work on hydrate anti-agglomeration is very limited. This work centers on the effect of NaCl and MgCl2 in mixtures of two vastly different anti-agglomerants. We use a model oil, water, and tetrahydrofuran as a hydrate-forming species. Results show that both salts—added in sufficient quantities—may result in the agglomeration of hydrates. Our results reveal a non-monotonic agglomeration behavior at low salt and/or large surfactant concentrations. Specifically, dissolved MgCl2 results in agglomeration more than the dissolved NaCl. Our measurements also show that the quaternary ammonium salt—i.e., quat—is more sensitive to dissolved salt than the nonionic rhamnolipid biosurfactant. In this work we show that the rhamnolipid biosurfactant is effective to a low concentration of 0.05 wt. %, yet quat has effectiveness down to 0.01 wt. %. The biosurfactant—with less toxicity and higher biodegradability—is an attractive alternative to chemical surfactants in anti-agglomeration. Results on the model systems show the promise for testing in real fluid systems and the field testing of the ideas.
Utilizing Modern Frac Baffles Improves Completion Efficiencies
Authors: Arispe Michael , Mueller Randy , Meaux Chris , Green Todd , Rojas Daniel
Published: September 2008

As hydrocarbon production costs rise, the need for greater completion and production efficiency is becoming increasingly important. The Haley Field in the Delaware Basin of West Texas has begun utilizing frac baffles in order to improve the overall efficiency of the multi-stage completion process. The frac baffles, which are strategically placed within the casing string, allow for zonal isolation by means of dropping a frac ball that seats on the frac baffle at the specified depth. The isolated zone is then ready to be perforated and fractured.

The process of utilizing frac baffles has proven to be more efficient compared to the traditional method of setting composite bridge plugs for zonal isolation. First, the need for wireline is reduced because there is no need to set composite bridge plugs. Additionally, the challenges experienced with setting and milling the composite bridges plugs are completely eliminated. Finally, the processes of perforating, stimulating, and coiled tubing milling have been dramatically improved.

In particular, coiled tubing milling of the frac baffles / balls has improved in the areas of milling speed, coiled tubing cycling, and circulation of milled particles returned. Most important, is the significant operational time savings, which allows the well to be brought on production faster.

Since October 2006, approximately 30 wells have been completed with this method. This paper provides an introduction to the frac baffle technology and shows how the utilization of frac baffles has improved the efficiency of the completion process. Specifically, the improvement with coiled tubing milling of the frac baffles / balls over the traditional composite bridge plugs is compared and discussed.
Well Test Analysis in Volatile Oil Reservoirs
Authors: Sanni M. , Gringarten A. C.
Published: September 2008

This paper discusses characterization of volatile oil reservoirs using well test analysis. For this purpose, typical well test behaviors were simulated with a one-dimensional single well compositional reservoir model, for different production rates; fluid composition and relative permeability curves, with bottomhole pressures above and below the bubble point pressure. It was found that, when the bottomhole pressure falls below the bubble point pressure during a drawdown, a high gas saturation zone is created around the wellbore with two-phase (oil and gas) flow, whereas single phase (oil) with the initial gas saturation remains away from the wellbore. During the subsequent build up, the gas created around the wellbore during the preceding drawdown condenses into the oil and the saturation in the near-wellbore region returns to the initial gas saturation. The log-log pressure-derivative behaviors below the bubble point correspond to a two-zone radial composite model, with decreasing mobility during drawdowns and increasing mobilities during build ups. The log-log pressure derivative plot of the build up reflects oil mobility distribution of the reservoir at the end of the preceding drawdown.

Knowledge obtained from the study was applied to the analysis of a well test in an actual volatile oil reservoir. Analysis results were validated with compositional reservoir simulation that included the effect of capillary number and non-Darcy flow.
Numerical Investigation of Gravitational Compositional Grading in Hydrocarbon Reservoirs Using Centrifuge Data
Authors: Ting P. D. , Dindoruk B. , Ratulowski J.
Published: September 2008

Fluid properties descriptions are required for the design and implementation of petroleum production processes. Increasing numbers of deep water and subsea production systems and High-Temperature-High-Pressure (HTHP) reservoir fluids have elevated the importance of fluid properties. Like rock properties, fluid properties can vary significantly both aerially and vertically even within well-connected reservoirs.

In this paper, we have studied the effects of gravity using experimental data available for five live oil and condensate systems (at high pressure and temperature) considering impact of fluid characterization effects. Under isothermal conditions and in the absence of recharge, gravitation will dominate. However, gravitational effects are not always significant for practical purposes. Since the predictive modeling of gravitational grading is sensitive to characterization methodology for some systems, experimental data from a specially designed centrifuge system is essential for calibration and as well as for quantification of these forces.

Numerical studies were performed using a calibrated EOS description based on the fluid samples taken at a selected point of each reservoir. Comparisons of measured data and calibrated model show that the EOS model quantitatively (within desired limits) and qualitatively described the observed equilibrium fluid grading behavior of the fluids tested. First equipment was calibrated using synthetic fluid systems as shown in Ratulowski et al.1 Then real reservoir fluids were used ranging from black oils to condensates (properties ranging from 27 API/1,000 scf/stb GOR to 57 API/27,000 scf/stb GOR). Diagnostic plots based on bulk fluid properties for reservoir fluid equilibrium grading tendencies have been constructed based on interpreted results, and sensitivities to model parameters estimated. The potential use of centrifuge data was investigated as an additional fluid characterization tool to construct more realistic reservoir fluid models for graded reservoirs (or reservoirs with high grading potential) have also been investigated.
Evolution of Single-Trip Multiple-Zone Completion Technology: How State-of-the-Art New Developments Can Meet Today's Ultra Deepwater Needs
Authors: Clarkson Brad , Grigsby Tommy , Ross Colby , Sevadjian Emile , Techentien Bruce
Published: September 2008

In the 1980s, economic conditions in the oilfield were demanding improvements in economic and completion efficiency, and all phases of the industry were requiring that strategies to improve cost be revisited. Sand-control completion methodologies were no exception; they were no longer capable of meeting the economic and completion-efficiency required to complete the long stacked intervals being attempted. To address this problem, a single-trip multiple-zone gravel-pack system was developed. The concept was successful for the targeted formations, but as with all new technologies, certain shortcomings concerning rathole intervals, complexity of the systems, and longer, more deviated wellbores prevented its use in all types of reservoir scenarios.

An improved version that was introduced in the early 1990's attempted to address these shortcomings. This system was successfully deployed and is still being run in the Far East today. However, limitations that were still experienced with the single-trip multiple-zone systems have prevented their wide spread adoption, causing them to remain a niche completion technique predominately used in the Far East and Italy.

Industrial drivers for deepwater development have again caused operating companies to revisit the viability of multiple-zone systems. Once considered too complex and risky for offshore operations; the development of the ultra deepwater lower-tertiary play in the Gulf-of-Mexico has provided the impetus for renewed interest in multi-zone concepts. This interest has been driving the development of the latest generation of the cased-hole multiple-zone system as well as an openhole multiple-zone frac-pack-compatible completion system.

The intent of this paper is to chronicle the development of cased-hole single-trip multiple-zone completion systems with a focus on the latest generation of these systems — the systems developed for deepwater applications. The paper will also discuss why previous systems have not proliferated globally to become an accepted mainstream sand-face completion technique.

The improved functionality of the newest system will be described and compared to the previous generation of systems. The integration testing to qualify the new multiple zone system is included in the discussions. Several installations have been planned, and the case histories will be included if available by paper time.
Employing Flow Assurance in an Offshore FEED Study
Authors: Grove Gary , Saether Geir , Estrada Giovanni P.
Published: September 2008

Flow assurance has taken on a primary role in FEED studies as of late and has become a standard tool to test design ideas, design changes, and operating strategies. The expectation from such studies is to lower the risk of flow assurance related problems, thereby minimizing both capital expenditures and operating costs. This discussion includes both the methodology and the results of the flow assurance study.

Production is located offshore and is made up of two platforms with a 25 kilometer flowline between them. The production stream is the combination of production from 5 wells and contains oil, water, and gas. This combined fluid presents primarily two flow assurance related problems: slugging and wax deposition.

In the case described herein, simulation tools incorporated the various data to create an understanding of the three typical operating scenarios: normal production operations and the respective flowline characteristicsplanned and un-planned shutdowns with resultant fluid cool-down behaviorstart-up methodology and subsequent transient behavior

A review of the methodology of the FEED study includes a discussion of what constitutes the necessary input data, how that data was used, how design changes were treated, and how other engineering aspects utilized these results for the final design.

The resulting simulated operations of the production system are presented. This includes the thermal behavior of the flowline, the changing fluid characteristics, and the associated temperatures and pressures with respect to the operating methodologies and mitigation techniques.

Finally, what makes this study possible is the use of state of the art dynamic simulation technology to delineate complex behavior in flowline systems. A discussion of the computing power and the software capabilities required for such an involved set of variables is provided.
Numerical Inversion of Laplace Transforms in the Solution of Transient Flow Problems With Discontinuities
Authors: Al-Ajmi N. , Ahmadi M. , Ozkan E. , Kazemi H.
Published: September 2008

Laplace transformation provides advantages in the solution of many pressure-transient analysis problems. Usually, these applications lead to a solution that needs to be inverted numerically to the real-time domain. The algorithm presented by Stehfest in 1970 is the most common tool in petroleum engineering for the numerical inversion of Laplace transforms. This algorithm, however, is only applicable to continuous functions and this limitation precludes its use for a wide variety of problems of practical interest. Other algorithms have also been used, but with limited success or popularity. A recent algorithm presented by Iseger in 2006 removes the restriction of continuity and provides opportunities for many practical applications. This paper exploits the useful features of the Iseger's algorithm in the inversion of continuous as well as singular and discontinuous functions that arise in the solution of pressure-transient analysis problems. The most remarkable applications are in the problems that require the use of piecewise continuous and piecewise differentiable functions, such as the use of tabulated data in the Laplace transform domain, deconvolution algorithms, and solutions that include step-rate changes as in the mini-DST tests.
Design Methodology for Swellable Elastomer Packers in Fracturing Operations
Authors: Evers Rutger , Young Dustin , Vargus Greg , Solhaug Kristian
Published: September 2008

During past 7 years, swellable elastomer technology has been introduced to the oilfield, and its acceptance has been so rapid that its scope of application has rapidly expanded. Swellable technology employs the principle of elastomeric expansion in hydrocarbon or water to form a permanent seal. With the increasing acceptance of this concept for the oilfield, new applications are being explored, and this paper will discuss the application of swellable elastomer packers (SEPs) in stimulation operations. These applications include acid stimulations and/or hydraulic fracturing operations. During stimulation operations, SEPs are subjected to a very specific set of conditions that significantly affect the sealing performance of the tool(s).

Three primary challenges must be addressed when designing SEPs for stimulation applications: The downhole conditions; i.e., the main parameters to which the tool will be subjected such as the downhole pressure and the average temperature of the sealing elements.Anchoring forces; i.e., the forces that occur from the shrinkage of the pipe during the treatment that subject the SEPs to additional forces that do not occur in conventional zonal-isolation applications.Thermal contraction of the sealing element; i.e., the contraction that occurs due to the injection of the stimulation fluids that will cause the temperature of the packer to drop. This phenomenon causes the sealing element to partially contract and will result in altered sealing properties, and ultimately, the loss of the pressure seal.

This paper describes the technical challenges and discusses resulting design methodology based on modeling (downhole parameters, anchoring forces) and laboratory testing (thermal contraction measurements) that have been developed to resolve these issues. This design methodology is not limited to stimulation applications but is applicable to any scenario with dynamic loads on SEP applications such as in water injection wells, etc.

Finally, case histories are provided to illustrate the successes that have been achieved using the design methodology described.
Completion of a Horizontal Well With Swellable Packers To Control Water Production
Authors: Cooper Katrina , McVey Adrienne , Schafer Daniel , Cox J. D. , Hilleary Nathan , Parker Donald , Crooks John
Published: September 2008

A long horizontal sidetrack, Well 01, was drilled into the thin Sag River formation in the Prudhoe Bay field in Alaska. Original plans included a well completion with a simple slotted liner. However, lost circulation and water-swept zones in the production section made a solid, cemented, and perforated completion necessary. At a certain point of total losses in the drilling of the well, seawater replaced the original drilling fluid. This allowed the well to be drilled, but complicated log interpretation and perforation placement from the seawater invasion.

There was a risk of a channel developing in the cement along the top of the well during the primary cement job due to the length of the horizontal section. A swept and faulted section in the middle of the well held the largest risk of excessive water production, therefore four packers which swell in specific reservoir fluids helped isolate this problematic section from a possible channel.

The horizontal length of the well, the high risk of losses, and the four swellable packers made the cement job challenging. The completion team had several options available for the cement job. The team ultimately chose a one stage job with additional excess volume and loss circulation material added. Closely monitored returns ensured the accuracy of the cement calculations, and a back-up plan for a top-down job was available if needed. The ultimate success of the primary job made the back-up plan unnecessary. After completing the primary cement job, just over 1300 feet of perforations were shot in the well.

The ability to change completion plans at the last minute allowed the installation of a successful completion with swellable packers which controlled water production. Also, an effective cement job proved possible even with multiple swellable packers in the well. Well 01 initially tested at just over 1000 barrels of oil per day with a 24% watercut. Currently the watercut remains at approximately 50%.
Acquiring Microresistivity Borehole Images in Deviated and Horizontal Wells Using Shuttle-Deployed Memory Tools
Authors: Christie R. , Elkington P. A. S. , McIlreath I. , Natros T.
Published: September 2008

Borehole images have broad applications in geological, petrophysical, and geomechanical studies. The advent of the small-diameter memory resistivity micro imaging tool improves operational efficiency in a broad range of well types. In spite of the tool's small size and weight, its design provides coverage and image quality that matches or exceeds that of previous generation imaging tools. It is deployed with or without a wireline and is not constrained by wireline data transmission rates because data are recorded to internal memory. Deploying the tool inside the drillpipe on the well shuttle facilitates access into highly deviated wells and past bad hole conditions without compromising borehole coverage.

Finding fractures in deep and tight rocks has become a high priority among explorationists around the world. Recent discoveries have shown that fractures can play an important role in the productivity of low-permeability plays, such as coalbed methane or shale gas. The only logging technology with the resolution to detect and identify these small features within the reservoirs is borehole imaging, where 2 mm details can be visualized.

Deviated wells in the Western Canadian Sedimentary Basin were logged using memory borehole imaging tools. The tools were housed inside a special drill collar while running in the hole, allowing rotation and circulation and were deployed using a messenger system and pressure pulses. The tools recorded microresistivity data to memory as the drillpipe was then tripped to surface. In all wells data was recovered, processed, and interpreted using software specially developed for this new memory-based technology. The resulting images were the equal of electrical borehole images obtained using conventional wireline deployment.

Using the memory imaging tool housed in the special drill collars protects the tools while tripping into the well. Since there is no wireline and no wet latches the shuttle system is more robust than conventional tool-pusher systems. This reduces risk and logging operation time while simultaneously delivering high-resolution borehole images that allow these fractured reservoirs to be properly evaluated.
Dual Laser Scheme Revolutionizes DTS Deployments
Authors: Jaaskelainen Mikko , Suh Kwang , Lee Chung
Published: September 2008

Distributed Temperature Sensing (DTS) systems have offered oil and gas companies critical asset monitoring solutions for years. DTS monitoring solutions provide real-time, dynamic temperature data with high accuracy, fine resolution and fast measurement speeds. DTS systems can provide tens of thousands of discrete temperature measurement readings along the complete length of an optical sensing fiber. These systems provide significant cost savings by identifying the location of leaks, optimizing gas lift operations, identifying under-performing zones, and monitoring thermal changes in steam drive applications. This paper discloses the first truly self-correcting DTS solution, which incorporates a revolutionary dual laser technology. This technology provides energy companies with the simplest, fastest, and most reliable DTS deployment available to the industry, combined with a capability to automatically correct for dynamic changes to the sensing fiber.
Successful Relief Well Drilling Utilizing Gyroscopic MWD (GMWD) for Re Entry into an Existing Cased Hole
Authors: Maehs Juergen , MacAfee Doug , Renne Steve , Cellos Greg , Srinivasan Ananth
Published: September 2008

In late 2007, a blow out occured in a well in the Gulf of Mexico. The blow out was caused by a leak in the production casing, which broached the surface and caused the well structure to collapse.

This SPE paper describes how the Apache Corporation utilized the latest state of the art Gyroscopic Measurement While Drilling (GMWD) tools to drill a relief well to stop the blow-out.

The S-shaped relief well was drilled towards the blow-out-well to perform a planned wellbore intersection. When reaching the blow out well, the production casing was milled and kill weight mud was pumped. This action stopped the blow out and enabled the operator to regain full control over the wellbore.

This paper also emphasizes the challenges while drilling this re-entry well: A 800 ft portion of the relief well had to be drilled with a closure distance of less than 40 ft to the pilot hole. Conventional MWD drilling systems which base their measurements on earth's magnetic field are incapable of providing reliable readings in areas with magnetic interference. Proximity to casing hinders the ability of conventional MWD tools to function and therefore, a drilling BHA with an integrating rate GyroMWD (GMWD) was deployed in this well. Rate gyro measurements are based on the earth's spin axis and can provide accurate real time survey data, including true north toolface and azimuth where earth's magnetic field is distorted.

This paper details an efficient way to drill a relief well and focuses on the innovative GyroMWD (GMWD) instrument that works in magnetic environments and close to metal casings.
The Use of Composite Materials in Repairing and Reinforcing Pipelines, Piping, and Structures
Authors: Rowe Adam , Alexander Chris
Published: September 2008

The purpose of this paper is to provide the oil and gas industry with an evaluation of composite repair and reinforcement systems to properly evaluate how composite materials should be used to repair and reinforce high pressure pipelines and offshore risers. The contents of the paper will include discussions on what critical elements should be evaluated for each composite system, items of caution and concern, and the importance of evaluation to ensure safe longterm performance. Based on a review of available research, composite materials can be used to reinforce damaged pipe materials. Specific examples include reinforcing mechanical damage subjected to cyclic pressure service and reinforcing corroded offshore risers.

Insights gained through the past decade can be used to apply composite repair technology to new systems and structures. The pipeline industry has led the use of these materials as a repair method in the same way the aerospace industry adopted this technology in the 1960s and 1970s. Using a "lessons learned" approach better positions us to understand the capabilities and limitations of this technology.
Detecting Thief Zones in Carbonate Reservoirs by Integrating Borehole Images with Dynamic Measurements
Authors: Li Bingjian , Najeh Hamad , Lantz Jim , Ali Rampurawala Mansoor , Gok Ihsan , Al-Khabbaz Mohammed
Published: September 2008

One of the key issues in creating a good reservoir model in carbonate reservoirs is the identification of the horizontal permeability conduits— "thief zones"— if any. In the Sabriyah field in Kuwait, dynamic measurements showed evidence of thief zones in the Mauddud formation. Early water breakthrough has occurred in some wells. Previous studies indicated that it was very challenging to detect the thinly layered thief zones using conventional openhole logs. This paper describes a methodology of recognizing the different types of thief zones in the Mauddud carbonate reservoirs using high-resolution image logs with calibration from core and dynamic measurements and by integrating image logs with nuclear magnetic resonance (NMR) and conventional openhole logs.

The Mauddud carbonates are Early Aptian in age and consist of grainstones, wackstones, and mudstones deposited in a ramp setting. Observations from production logging tool (PLT) and production data indicated that there are a few thief zones in different levels within the vertical Mauddud sequence. A previous core study shows that the fractures in Mauddud formation are short (<10 cm) and concentrated in diagenetically cemented layers. The fractured thin layers are believed to be the principal type of thief zone. Another type of thief zone is associated with better-developed vuggy porosity. This study shows both fractured and vuggy porosity–related types of thief zones can be potentially detected through integration of high-resolution image logs with PLT, NMR, and conventional logs. In addition, methodologies of estimating fracture permeability and porosity-related permeability based on logs are also proposed. The log-estimated permeability determined using this approach fits better with the production profile and can then be used to evaluate the thief zones in a more quantitative manner.
Nuclear Energy for Unconventional Fossil-Fuel Resource Recovery
Authors: Badruzzaman A. , Hedges J. , Demayo T. , Sigworth H.
Published: September 2008

Nuclear energy is typically used to supply electricity, but a new generation of novel, inherently safer reactors can supply high-temperature steam for a number of petroleum, coal and chemical industry applications. Potential applications include recovery from unconventional petroleum sources such as oil sands and heavy oil, coal-to-liquids conversion, and production of hydrogen for refineries, chemical industries and possibly future transportation. Currently, natural gas is the typical source of the process heat and its use in these applications is likely to increase, as a greater reliance is placed on these resources to meet the projected growth in energy demand. This will increase greenhouse emissions from fossil fuel use. Techniques, such as carbon dioxide capture and sequestration, proposed to mitigate greenhouse gas emission from fossil-fuel based power and heat generation are in early stages of development and face technical and economic challenges. Nuclear power and heat generation emits almost no greenhouse gases. In addition, use of nuclear energy can free-up fossil fuels for other unique applications. These advantages, together with energy security concerns, improved safety and reliability, and reduced cost of nuclear plants, have renewed interest in this technology.

The paper explores the potential benefits and challenges of using nuclear energy in enhanced recovery from unconventional fossil-fuel resources. The associated economics and corresponding potential reduction in CO2 emission are examined. Both appear substantial in some applications, such as production from heavy oil reservoirs and oil sands. Economic benefits are more questionable in other applications such as in hydrogen production, and would require technological breakthroughs. Challenges facing nuclear energy include concerns of proliferation, waste disposal, public perception, demands on various resources, and licensing of novel high-temperature reactors. Resolution of power and temperature rating compatibility issues and siting constraints which may arise in some of the unconventional recovery operations will be additional challenges. However, these challenges may be less inhibiting than previously thought. The paper also briefly summarizes government-industry initiatives being discussed in the US to develop novel nuclear reactor concepts for these uses.
Experimental Study and Modeling of Cuttings Transport Using Foam with Drillpipe Rotation
Authors: Duan Mingqin , Miska Stefan , Yu Mengjiao , Takach Nicholas , Ahmed Ramadan , Hallman John
Published: September 2008

Although rotary drilling is being used in most wells, the impact of drillpipe rotation on hole cleaning during foam drilling has not been investigated. There has been no single predictive tool developed to address pipe rotation effects on foam drilling. This paper presents the first study of cuttings transport using foam with pipe rotation under simulated downhole conditions.

A field-scale, high pressure high temperature wellbore simulator with a 73-ft long, 5.76″ by 3.5″ eccentric annular test section was used to investigate the effects of pipe rotation, foam quality and velocity, downhole pressure and temperature on cuttings transport and pressure losses in a horizontal wellbore. Experiments were conducted with backpressures from 100 to 400 psi and temperatures from 80 to 160 degrees F. Pipe rotary speeds were varied from 0 to 120 RPM with foam qualities ranging from 60% to 90% and foam velocities from 2 to 5 ft/s.

It was found that pipe rotation not only significantly decreases cuttings concentration in a horizontal annulus but also results in a considerable reduction in frictional pressure loss. The reduction in cuttings concentration is up to 40% at a medium foam velocity (3 ft/s) when pipe is rotated up to 120 RPM. The decrease in frictional pressure loss is up to 50% at a medium foam velocity and is more than 60% at a low velocity. Using a higher foam velocity or quality also improves hole cleaning, however, pressure losses are significantly increased.

A mechanistic model and an associated computer simulator were developed for practical design and field applications. It can be used to predict cuttings concentration, bed height and pressure drop during horizontal foam drilling with various pipe rotary speeds, eccentricities, foam qualities and velocities under different pressure and temperature conditions. Comparisons between model predictions and experimental results show that the difference is less than 15% in most of the cases.