bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gaslift Optimization - Claymore Field
Authors: Kleyweg D , Tiemann W D , Dalziel S G 
Published: December 2007

ABSTRACT
The Claymore field has been developed with a single 36-slot integrated platform. Wells drilled from the platform are deviated up to 70° to reach reservoirs in the Lower Cretaceous Sands, the Upper Jurassic Claymore Sands, the Zechstein Limestones and Dolomites and the Carboniferous Sands. Produced fluids from the reservoirs vary considerably in PVT properties, but are all of the low-GOR type.
Gaslift was selected as the artificial-lift system for the field and compressors were installed with a total throughput of 200 MMSCF/D at a discharge pressure of 1,600 psig.
Wells are typically completed with 5-1/2" plastic-coated, premium threaded tubing equipped with side-pocket gaslift mandrels. The gaslift design and mandrel spacing are based on 12,000 BF/D with a 50% watercut using up to 10 MSCF/D of gaslift gas. Because of the high gas rates needed, dual-valve stations (two mandrels one joint apart) are used. Fig. 1 shows such a well completion.
Topside Facilities Design for Hutton TLP
Authors: Wingate Peter M , Hasz John W , McGee Michael D 
Published: December 2007

ABSTRACT
The Hutton North Sea field is to be developed using the world's first commercial Tension Leg Platform (TLP). This paper explains how the choice of a TLP, with its dynamic behaviour and structural configuration, affected the design of the topside facilities. The problems faced by facilities engineers are described as are the methods used to resolve them. The nature of the problems described are general to TLPs, consequently the material presented is applicable to designs of the future.
The Design, Construction & Operation of the Helicopter Underwater Escape Trainer
Authors: Urquhart A E 
Published: December 2007

Abstract
During the early days of helicopter operations, mainly in the Royal Navy, some aircrew lost their lives after a controlled ditching or a heavy landing onto the sea, when they became trapped in an aircraft which capsized and sank. The subsequent inquiries often proved that some of the victims were fit enough to have effected an escape and the cause of death was usually attributed to disorientation during the capsize and sinking. In some cases, the problems associated with disorientation were exacerbated by the accidental or positive operation of inflatable lifejackets, which made escape from the submerged helicopter virtually impossible.
Concern was such that helicopter underwater escape training facilities were built by the Royal Navy. The Royal Navy's commitment to helicopter underwater-escape training is shown by the fact that all helicopter aircrew and others whose duties cause them to fly regularly, must complete initial helicopter underwater escape training followed by refresher training every two years. (Reference No. 1)
Civil helicopters hopefully are not likely to be subjected to the possibility of being shot from the skies and descending in an uncontrolled manner. Should a civil helicopter have to ditch, due to some mechanical or electrical failure, it is reasonable to predict that it may do so in a controlled manner, with the pilot either taking the positive decision to ditch the helicopter, or being forced to do so.
A Comparison of the Performance, Cost and Environmental Effects of Diesel-Based and Low-Toxicity Oil Mud Systems
Authors: Hinds A A , Smith S P T , Morton E K 
Published: December 2007

ABSTRACT
The paper reviews and analyses performance, toxicity and cost data generated during the development and field application of a low-toxicity (LT) oil mud system. During the development phase approximately twenty "white mineral oils" were studied and evaluated as prospective diesel-oil substitutes. Their mud-formulating properties and toxicity to a variety of aquatic species were compared with those of diesel oil. The LT oil muds, to date, have been used successfully to drill over seventy wells.
The advantages of drilling with an oil-based mud are well documented. These include improved well bore and formation stability, high lubricity, fluid stability at high temperatures and pressures, corrosion protection and tolerance to contaminants. However, the LT oil muds offer an additional advantage, namely, environmental compatibility, not hitherto available, with diesel-based systems.
Government regulations restricting the discharge of oil and other toxic substances into the marine environment have precluded the use of diesel-oil systems in certain areas. Further, operators have often found cuttings-wash systems to be ineffective for removing diesel mud from cuttings. Recently, several governments have approved the direct discharge of LT oil mud cuttings which makes these systems cost effective and thus highly attractive.
The white mineral oils were found to contain significantly less aromatic hydrocarbons than diesel oil, were less toxic and fluoresced to a lower degree.
Kinematic viscosities ranged from 6.6 to 1.0 at 40°C providing great flexibility in adjusting the rheological properties of the mud to meet specific conditions. Approximately eleven oils have been used in mud formulations and successfully employed in drilling wells.
The LT oil muds were found to perform as well as diesel-based systems with a marked improvement in penetration rate in many cases.
Toxicity studies were conducted by several reputable laboratories in Europe and the United States. The results indicated that the non-toxic muds had LC50'S which ranged from 10,000 ppm to 50,000 ppm for the brown shrimp Crangon crangon; and 100,000 ppm for the plaice, Pleuronectes pletessa. Corresponding results for the diesel oil systems were 160 ppm C. crangon and 4,700 ppm P. platessa. Several of the LT systems have been approved by European governments for the direct discharge of unwashed cuttings.
Better Turbodrilllng Can Give Dramatic Reductions in Drilling Costs
Authors: de BRUIJN H J 
Published: December 2007

ABSTRACT
A field performance analysis of turbine-driven bits assumes that the rate of bit penetration is roughly proportional to the mechanical power available from the turbine. The variations in bit performance can then be explained by variations in turbine power output, which is a function of torque and rotational speed and thus is controlled by weight on bit (WOB). The data show that natural diamond bits give their best performance at high WOB, whereas polycrystalline diamond compact (PDC) bits perform best at low WOB. The data further suggest that at optimum WOB the rate of penetration could be improved by 200–300%.
A turbine tachometer could enable drilling to be performed at exactly the rpm at which the turbine develops its maximum power and thus gives the highest rate of penetration. Calculations show that the cost per metre drilled may thus be reduced by as much as 50%.
The drilling rate can further be increased by improving the hydraulic capabilities and efficiency of the rig, using:
Larger drillpipe, e.g. 5 1/2" instead of 5", to take advantage of the larger bore. Drill collars and Hevi-Wate drillpipe with larger inside diameter. A minimum amount of drill collars and Hevi-Wate drillpipe for the maximum WOB. Higher standpipe pressures (max. 500 psi).
The reduction of frictional losses in the hydraulic system of the rig thus obtained, together with the higher standpipe pressure allowed, would enable the operator to run turbines with more stages and to circulate more mud, resulting in up to 50% higher turbine output. Calculations show that in this way a further reduction of perhaps 25% can be obtained on the cost per metre drilled.
Underwater Manifold Centre - Drilled- Cuttings Disposal System
Authors: Biddlestone P A 
Published: December 2007

ABSTRACT
During the construction of the Central Cormorant Underwater Manifold Centre (UMC), it was recognised that the cuttings produced during the drilling of template wells would interfere with UMC operations, if deposited on top of the structure.
A dual system was developed and installed on the Stadrill (the unit planned to drill the wells) to remove the cuttings from the rig to the seabed away from the UMC.
Development Of A Diverless Subsea Flowline And Control-Line Connection System
Authors: King C R , Ostocke H D , Best McEvoy M J A 
Published: December 2007

ABSTRACT
The laying and coupling of subsea flowline bundles is an important feature of subsea oil and gas production systems. A critical part of the operation is the final pull-in, alignment and connection of the flowline to fixed seabed production structures.
This paper traces the development of equipment to accomplish the diverless connection of flowlines and control lines and the field experience to date.
An Investigation of a High-Strength Proppant Tail-In at McAllen Ranch Field
Authors: Lindley B. W. , McGhee B. F. 
Published: December 2007

ABSTRACT
Producing deep, geo-pressured, extremely tight gas reservoirs which have received massive hydraulic fracture treatment, creates severe crushing stresses on proppant placed in the fractures. Several high strength proppants are available on the market. While these proppants are superior to frac sand they are considerably more expensive. The question of the producer is one of pure economics. In some cases economics of a prospect may be marginal ; therefore, the operator considers alternative measures. One alternative is modification of the proppant schedule to place a regular strength proppant deep in the fracture and a high strength proppant next to the wellbore where closure stresses will be greatest.
This paper discusses the evaluation of proppant placement in a massive hydraulic fracture treatment "tail-in" technique. The term "tail in" is used to describe the final proppant stage of a multi-stage fracture treatment. A new evaluation method was developed to determine placement of this tail-in stage. For this new method the leading stages of proppant laden fluid were tagged with a long half-life isotope, 74 days. The tail-in of proppant laden fluid was tagged with a short half-life isotope, 8 days. Comparison of calibrated radiation logs recorded before and immediately after fracture treatment define the placement of proppant tagged with both isotopes. A third radiation log, recorded at the appropriate time measures decreases in radiation of both isotopes. Processing data from these three logs in a mathematical model enables calculation of proppant placement during treatment.
Four wells were treated in Forest Oil Corporation's McAllen Ranch Field, Hidalgo County, Texas. Of these four wells, one was treated with a "tail-in" technique and the other three with a 100% bauxite simulated "tail-in" technique. In these four wells, the proppant was tagged with two different radioactive isotopes to determine If the "tail-in" fraction was placed next to the wellbore. In all four wells, the evaluation indicated both proppants next to the wellbore. Factors causing this were diversion to different members during treatment and override of the leading proppant. Without proper placement of the bauxite "tail-in", extreme closure pressures near the wellbore would crush the regular strength proppant and loss of reserves would result.
Post-frac buildups were performed on two wells which had been subjected to approximately the same closure pressure. The well with 100% bauxite had much greater fracture flow capacity, than did the well with a tail-in treatment.
Experience gained from these four wells indicate that the "tail-in" technique of stimulation was not successful at McAllen Ranch Field.
Predicting Phase Behavior of Mixtures of Reservoir Fluids With Carbon Dioxide
Authors: Grigg R. B. , Lingane P. J. 
Published: December 2007

ABSTRACT
The use of an equation of state to predict phase behavior during carbon dioxide flooding is well established (see, for example, Yarborough20 and Whitson21 and references therein).
There is consensus that the characterization of the C7+ fraction, the grouping of this fraction into "pseudo components," and the selection of interaction parameters are the most important variables. However, the literature is vague as to how to best select the pseudo components, especially when aiming for a few-component representation as for a field scale compositional simulation.
Single-contact phase behavior is presented for mixtures of Ford Geraldine (Delaware), Maljamar (Grayburg), West Sussex (Shannon), and Reservoir D reservoir fluids, and of a synthetic oil C1/C5/C16, with carbon dioxide.
One can reproduce the phase behavior of these mixtures using 3-5 pseudo components and common interaction parameters. The critical properties of the pseudo components are calculated from detailed oil characterizations. Because the parameters are not further adjusted, this approach reduces the empiricism in fitting phase data and may result in a more accurate representation of the system as the composition of the oil changes during the approach to miscibility.
Synergy of Core Petrophysigal Measurements, Log Data, and Rock Examination in Carbonate Reservoir Studies
Authors: Nurmi Roy D. , Frisinger M. Rusty 
Published: December 2007

ABSTRACT
The pore system characteristics of a wide range of limestone rock types have been reviewed including: reef skeletal framework, chalks, calcareous sands, and mud-stones with and without the presence of grains. The emphasis of the present discussion is on carbonate reservoirs that originated as calcareous sands. A synergistic study of the geological, petrophysical, and logging data of these rocks provided insight into their reservoir characteristics. For example, the geological analysis of porosity/ permeability crossplots on semi-logarithmic paper produced linear, or at least discrete, trends for each different depositional rock types. Furthermore, the attempts to understand the underlying relationships between the porosity and permeability of these depositional rock types also permitted a better understanding of the affects of diagenesis, dolomitization, and fracturing in more quantitative terms.
The diagenetic, or secondary, creation of porosity in carbonates, including grains tones, is quite common. In cases of moldic porosity and intragranular microporosity in grainstones this secondarily created porosity can be relatively isolated from the intergranular pore system. The secondary fraction of the pore volume was recognized and quantified through the analysis of porosity/permeability plots and SEM examination of the core and pore casts. Since this pore system data is relatable to the geological rock types and facies mapped and modeled by geologists, it is then possible to better understand the large-scale distribution of pore types and permeability. Furthermore, when the more thorough understanding of carbonate pore systems is related to the well-log data there is an improvement both in interpretation of logs and in the ability to map reservoir and depositional units.
Comparison of Uniaxial Strain and Hydrostatic Stress Pore-Volume Compressibilities in the Nugget Sandstone
Authors: Lachance D. P. , Andersen M. A. 
Published: December 2007

ABSTRACT
This paper presents a comparison of rock compressibilities determined under two different stress states. One stress state was the traditional though unrealistic hydrostatic stress method; the other was the more realistic though more complicated uniaxial strain (triaxial stress) with pore pressure method. Compressibilities were determined by both stress methods on Nugget sandstone core plugs from the Rocky Mountain Overthrust Belt. The resulting relationship between the two types of compressibilities did not match with previously published predictions.
The uniaxial strain pore volume compressibilities averaged about one-third of the corresponding hydrostatic stress pore volume compressibilities. This was a greater difference than predicted using standard practices. Also, the uniaxial strain data varied only slightly between samples, while the hydrostatic stress data exhibited a greater range of values. From the uniaxial strain measurements, bulk volume compressibility of the Nugget sandstone is constant over the porosity and pressure range of the reservoir. Pore volume compressibility can therefore be easily determined from the porosity and the bulk volume compressibility.
Design and Operation of a CO2 Tertiary Pilot: Means San Andres Unit
Authors: Stiles L. H. , Chiquito R. M. , George C. J. , Long L. D. 
Published: December 2007

ABSTRACT
This paper describes the design, implementation and operation of a CO2 tertiary pilot in the Means San Andres Unit, Andrews County, Texas. The pilot consisted of five wells on 1.5 acres. Detailed geological studies showed the reservoir to be more heterogeneous than broader studies had indicated. Pilot operations and evaluation were complicated by a dual permeability zone. Special tests to define this interval are described. Evidence of additional oil recovery was shown from both log analysis and fluid samples.
Frictional Pressure Losses for the Flow of Drilling Mud and Mud/Gas Mixtures
Authors: Langlinais J. P. , Bourgoyne A. T. , Holden W. R. 
Published: December 2007

ABSTRACT
The calcuation of single phase and two phase flowing pressure gradients in a well annulus is generally based on an extension of empirical correlations developed for Newtonian fluids in circular pipes. Various techniques for extending pipe flow correlations to an annular geometry have been presented in the literature which involve the representation of the annular well geometry with an equivalent circular diameter and the representation of non-Newtonian fluid behavior with an apparent Newtonian viscosity. Unfortunately, little experimental data have been available which would allow a comparison of the relative accuracy of the various proposed techniques.
In this study, experimental pressure gradient data have been taken in two 6000 ft. wells. Frictional pressure losses for single phase flow (mud only) in two annuli were compared to values predicted by the Bingham Plastic and Power law Models. These calculations utilized the equivalent diameters defined by the Crittendon criteria, the hydraulic radius, and the slot approximation. Also, total pressure difference for two-phase flow was measured for one annular geometry. This data was compared to that predicted by the Poettmann and Carpenter, Hagedorn and Brown, Orkiszewski, and Beggs and Brill correlations.
Comparison of experimental data with the various prediction techniques was favorable, each having advantage in certain situations. For the data investigated, the Crittendon criteria using a Bingham Plastic Model gave the best results. The two phase flow data was best predicted by the Hagedorn and Brown correlation utilizing a hydraulic radius equivalent diameter.
A Laboratory Study of the Tapered-Quality Steam-Water Process on a Light Oil
Authors: Cheung Y. L. , Brown Alfred , Huang W. S. 
Published: December 2007

Abstract
The tapered-quality steam-water process, in which steam injection is converted to water injection via gradually decreasing steam qualities, is described. Laboratory tests performed in linear sand packs on a 43°API gravity crude oil show that (1) steam injection is very effective in recovering light oil, and (2) the tapered-quality steam-water flood is at least equal to, and potentially better than, the conventional steam flood in energy efficiency.
Rheological Characterization of Crosslinked and Delayed Crosslinked Fracturing Fluids Using a Closed-Loop Pipe Viscometer
Authors: Gardner D. C. , Eikerts J. V. 
Published: December 2007

ABSTRACT
A closed-loop, high-temperature pipe viscometer was used to evaluate the effects that shear intensity, shear duration, temperature, and time have on the apparent viscosity of cross-linked fracturing fluids. Results indicate that much higher gel viscosity can be obtained in the fracture with certain types of delayed cross-linking agents than can be achieved with most of the conventional titanate cross-linkers so widely used in the industry. The maximum achievable apparent viscosity reached by either the titanate or zirconate cross-linked gels studied appears to be most affected by the level of shear or energy input encountered during the initial cross-linking phase.
A Multi-Function Compensated Spectral Natural Gamma Ray Logging System
Authors: Smith H. D. , Robbins C. A. , Arnold D. M. , Gadeken L. L. , Deaton J. G. 
Published: December 2007

ABSTRACT
A natural gamma ray spectroscopy togging system has been designed which incorporates active compensation for differences in borehole conditions into the least squares calculation of the K-U-Th elemental concentrations. A low atomic number toolcase allows gamma rays in the photoelectric energy region to be detected, while a coincidence gain stabilization technique distinguishes formation gammas from those originating in the stabilizer source. These features permit additional measurements of formation lithology in open holes and mean casing thickness in cased wells.
A Simplified Method for Water Coning Predictions
Authors: Kuo M. C. T. , DesBrisay C. L. 
Published: December 2007

ABSTRACT
Numerical simulation was used to determine the sensitivity of water coning behavior to various reservoir parameters. The simulation results were then used to develop a simplified correlation for water coning predictions. The correlation is general since the sensitivity studies cover a wide range of reservoir parameters (ratio of vertical to horizontal permeability from 0.01 to 1.0; perforated interval from 20 percent to 80 percent of oil zone thickness; production rate from 500 to 2000 RB/D gross fluid; mobility ratio from 1.0 to 10). The correlation is valid to predict watercut performance for most reservoirs with strong bottom water drives except those with local barriers present, those with a high degree of stratification (Dykstra-Parsons Permeability Variation &gt; 0.8), or those with a thick oil-water transition zone.
With the correlation programmed on a hand-held calculator, field engineers can conveniently predict critical rate, breakthrough time and watercut performance. Compared to complicated numerical models, the correlation is particularly useful when detailed reservoir data are not available, or when decision time and project cost are limited. Field engineers can use the simplified correlation to compare watercut performance for various operating strategies and make appropriate decisions for production operations.
Predicting Gas Well Performance Coning Water in Bottom-Water-Drive Reservoirs
Authors: Kabir C. S. 
Published: December 2007

ABSTRACT
Depletion strategy of a gas reservoir underlain by an active water drive requires careful thought and planning. Producing rate and completion interval are the apparent key considerations in a depletion scheme because of the potential water coning that may affect the ultimate recovery. As this study indicates, both the considerations are relatively unimportant from the stand point of theoretical ultimate recovery.
The primary purposes of this investigation are to develop an analytical solution for the water coning problem and to provide guidelines on the depletion strategy in thin reservoirs (&lt; 60 ft). A systematic study of the variables indicates that permeability and pay thickness are the most important variables governing coning phenomenon. Other variables such as penetration ratio, horizontal to vertical permeability ratio, well spacing, producing rate, and the impermeable shale barriers have very little influence on both the water-gas ratio response and the ultimate recovery.
Generalized analytical solutions that are developed in graphical form, using a numerical coning simulator, allow a multitude of calculations. These calculations include predicting a well's behavior with or without a production history, determining an economical withdrawal rate, generating a rate-time profile, and estimating a breakthrough time. The type curves could also be used as a diagnostic tool to identify possible completion problems.