bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of Splitting the Hydrocarbon Plus Fraction: First Step in Tuning Equation of State
Authors: Al-Meshari Ali A. , McCain William D. 
Published: December 2007

Abstract
Volumetric data and phase behavior of volatile oils and gas condensates are very sensitive to the fluid composition and the properties of the plus fraction. Since the plus fraction of a reservoir fluid has some uncertainty in its measured molecular weight, the equation of state, EOS, is generally not predictive unless its parameters are tuned to match the experimental data. Characterization of the plus fraction, which is important in tuning the EOS, consists of splitting the plus fraction to single carbon number groups, assigning critical pressure, critical temperature and acentric factors to each single carbon number group, SCN, and then grouping single carbon number groups to multiple carbon number groups, MCN.
Direct measurement of the critical pressure, critical temperature and acentric factor of the plus fraction is not practical. Several authors have shown that erroneous predictions and calculations can result if the plus fraction is used directly as one component in EOS calculations and that use of the extended composition of the measured plus fraction will give more accurate PVT predictions for crude oil and gas-condensate mixtures.
To tune EOS three main steps should be followed: (1) Extend the measured composition into SCN, assign critical properties and acentric factor for each SCN, and match saturation pressure using the extended composition (2) Group SCN into pseudo-components, group the properties of the pseudo-components, and rematch the saturation pressure using the grouped composition and (3) Match PVT properties.
The objective of this study is to find an accurate method for splitting the hydrocarbon plus fraction to single carbon number groups and then validate the proposed method by using experimental extended fluid composition of different reservoir fluids. The proposed method was compared to other splitting methods published in the literature.
New Offshore Rigless Intervention System
Authors: Harris David , Adams Paul G. 
Published: December 2007

Abstract
Application
This paper will discuss the successful use of a new "Rigless Intervention System" [ RIS] as an alternative to the use of a Drilling Rig or Workover Rig for the Abandonment of Conductors, Pre Installation of Conductors, Sidetrack and Whipstock operations. The RIS system has also been used on a Tension Leg Platform for the pulling of Production Risers because deck load limitations ruled out the use of a workover rig.
With rigs becoming increasingly scarce, operators are being forced to delay abandonment and drilling plans for weeks, even months. For those operators with the foresight to anticipate this shortage, they have found an environmentally friendly hydraulic rigless intervention system as a means of extracting and pre-installing conductors without a rig.
The system has been performing for a number of operators in the Gulf of Mexico and internationally. The system reduces the amount of time and expense associated with installing conductors by pre-installing them prior to the arrival of the drilling rig, using the system to handle the joints and then for them to be driven with hydraulic hammers. On the conductor extraction side, the system speeds the process of abandoning multiple wells on fixed platforms.[See Fig. 1]
Case Study in Water Shutoff Fluid Placement Using Straddled Through-Tubing Inflatable-Packers Technique
Authors: Kelkouli Redha , Razouqi Maen , Al-Shaheen Saeed , Al-Khamees Abdul Rasool , Dashti Abdulaziz Abdulla 
Published: December 2007

Abstract
Most of the wells in Sabriya Field (Northern Kuwait) produce from reservoirs, where multiple layers are opened to production. Problems related to non-desired water production are drastically affecting the oil production, and have been an ongoing concern. The exclusion of this water represents a challenging task by itself especially in case of multiple zones interval simultaneously producing, and where completion of the wells restricts considerably the convoyed down-hole tools configuration
This paper covers water shut off case history of an oil producer that has shown according to the production data an increasing water production figures. The nature of water problem and the fact that the targeted section is located in-between multiple oil producer zones revealed the necessity of a complex thru tubing zonal isolation solution before performing the water shut-off treatment. Temporary coiled tubing conveyed straddle system was created using two thru tubing inflatable packers, isolating the top and bottom perforated zones in order to provide both proper zonal isolation and accurate treatment placement. The post water shut off treatment showed up to 70% water flow reduction from the targeted layer has been achieved.
Flow Rate Effect on Two-Phase Relative Permeability In Iranian Carbonate Rocks
Authors: Alizadeh A. H. , Keshavarz A. R. , Haghighi M. 
Published: December 2007

Abstract
The effect of flow rate on relative permeability curves has been investigated in very tight Iranian carbonate rocks. Core samples were prepared from outcrop of Asmari formation. Asmari formation represents huge oil carbonate reservoirs in Iran. This formation belongs to Oligocene-Miocene period and is mainly limestone. The dynamic displacement experiments were performed at three different flow rates. In all experiments, we injected both water to displace oil and oil to displace water and relative permeability curves were generated with the Jones and Roszelle method for both water-flooding and oil-flooding experiments.
We found a critical rate in which we could not obtain any relative permeability curves above this rate. This critical rate represents the limit of injectivity capacity of each core sample. We observed that in the water-flooding process, water relative permeability curves and its end points were not affected by flow rate. However, it was detected that the oil relative permeability decreases at lower flow rates. This variation vanishes at the central saturation points. During oil-flooding experiments, we also observed the same no rate effect in water relative permeability curve but in the oil relative permeability curves, although it was seen the flow rate effect, it was not found any meaningful trend in the curves and its end-point saturations.
We found hysteresis effect in both water and oil relative permeability curves. At higher flow rates, the effect of this phenomenon increases in water relative permeability curves while the hysteresis effect decreases in the oil relative permeability curves.
Fractured Wellbore Stress Analysis: Sealing Cracks To Strengthen a Wellbore
Authors: Wang Hong (Max) , Towler Brian F. , Soliman Mohamed 
Published: December 2007

AbstractWellbore pressure containment, the maximum pressure that a wellbore can withstand before whole drilling mud begins to leak off into formations, defines the upper bound of the mud weight window. Drilling costs are heavily associated with this mud weight window in terms of expensive casing programs or nonproductive time because of narrow mud weight windows.Although various methods have been developed using different materials for curing mud losses, the performance has been poor as a result of the lack of engineering design for the materials and placement techniques. The commonly used "trial and error" approach reveals inadequate understanding of the challenge, although a number of advances have been accomplished in recent years.In this paper, results are reported from a fundamental study aimed at revealing the basic physics that control the success of treatments strengthening wellbores or widening the mud weight window. It first focuses on reviewing and identifying factors that can reduce the upper bound of this mud weight window, followed by analysis of wellbore strengthening that can increase this upper bound of mud weight window, especially by sealing hydraulically conductive cracks at the wellbore.
Calculation of Flowing Bottomhole Pressure Constraint Based on Bubblepoint-Pressure-vs.-Depth Relationship
Authors: Obeida T. A. , Mosallam Y. H. , Al Mehari Y. S. 
Published: December 2007

Abstract
Thick reservoirs usually have variations of PVT properties such as bubble point pressure and dissolved gas oil ratio with depth. A considerable effort usually spent to describe such properties to be used in dynamic models either in Black Oil or compositional simulators. However, during predictions many dynamic models set the BHP constraint as a constant value for all producers in the entire reservoir regardless of perforations depth. Usually this constant value is close to the average bubble point pressure or a little higher to ensure single phase (oil) production and not considering changing of bubble point pressure with depth.
The above procedure introduces uncertainty regarding well potential, which involves a risk of not presenting accurate well performance in the simulator and would impact oil production and recovery forecasts.
The proposed method was developed to calculate following BHP constraint based on bubble point pressure versus depth relationship for each grid cell in the dynamic model, thus creating 4D-array (I, J, K, BHP constraint) for the entire reservoir.
The proposed method is fully automated and tested to assign BHP constrains in schedule section of huge dynamic model (2.6 million cells) with 600+ wells.
Two prediction cases were tested (each case run twice, one run with constant BHP constraint for all the produces and the other one using variable BHP constraint recommended by the proposed method) to evaluate the impact of BHP constraint on production and oil recovery forecasts.
The results of these two runs showed a considerable difference in length of oil production plateau and oil recovery forecast, but negligible differences in gas oil ratio.
The proposed method could be used for any dynamic model with vertical and/or horizontal variation of bubble point pressure to calculate an optimum BHP and thus WHP to maximize production rate without the risk of introducing gas phase at reservoir conditions.
Field-Test Results of an Acoustic MWD System
Authors: Neff J. M. , Camwell P. L. 
Published: December 2007

Abstract
Acoustic telemetry (AT) MWD systems are finally coming of age as a commercially viable alternative to mud pulse and electro-magnetic propagation systems. Building upon our theoretical and experimental knowledge and understanding of communicating through the steel walls of drill pipe we have developed a practical, high data rate, acoustic telemetry system for use in drilling assemblies. We utilize one of the passbands that allow acoustic signals to propagate through the periodic structure of typical drill pipe.
In this paper we describe the field test program used to evaluate our through-bore AT system performance and demonstrate its practical and commercial applications. The program was limited to shallow, vertical and directional land wells (&lt;2,500m) drilled with jointed pipe using both kelly and top drive systems. The AT tool was placed in a number of different locations in both rotary and steerable BHAs. A variety of operational modes and configurations were tested. The system performance was evaluated for various carrier frequencies and baud rates (5, 10 and 20bps) while signal, battery, decoding and reliability data were recorded and evaluated. The AT system performance was found to be acceptable for commercial applications. Significant time savings and improved drilling efficiency were demonstrated. Test results, including the present AT system limitations, are presented. As far as the authors are aware, the AT system has achieved the highest wireless data rates in a drilling environment compared to mud pulse and EM telemetry.
The system as it exists today is suitable for use as a rig-operated, automated, survey-on-connection tool in shallow wells. Several technical innovations have enabled the successful development of our system including advanced digital signal processing techniques and novel signal-to-noise enhancement techniques, as confirmed by field trials.
Effective Matrix Acidizing in Carbonate Reservoir – Does Perforating Matter?
Authors: Bartko Kirk M. , Chang Frank F. , Behrmann Larry A. , Walton Ian C. 
Published: December 2007

Abstract
It is well known that in cased-hole completions productivity is enhanced by maximizing shaped charge penetration and shot density while minimizing perforation damage. However, in tight carbonate reservoirs, creating deep and clean perforations may still not be enough to generate the desired productivity. Therefore the wells are often stimulated by a matrix acidizing treatment after the perforating. A prevalent mind set in the industry is that acid dissolves the perforation debris and creates wormholes that bypass the perforating and other near wellbore damage, therefore perforating design is not important as long as it serves the purpose of puncturing through the casing.
This paper presents recent research that looks into the impact of perforating on matrix acid stimulation. Large scaled single-shot perforating tests were conducted using real shaped charges to perforate carbonate core samples under downhole conditions. Acid was then injected into the perforations to create wormholes. The acid injectivity was measured, and the wormhole patterns through perforations generated by different perforating designs were compared using CT scans. It was found that clean perforations promote not only higher acid injectivity, but also initiate straighter and more dominant wormholes, while the un-removed perforation debris causes the wormhole to start with a more deviated pattern.
In the paper the required perforating design to create clean perforations is discussed for low permeability gas reservoirs. The effect of perforating with acid in the wellbore as the completion fluid is also examined. The implications and suggestions to safely apply the technique of perforating with acid are discussed.
Constant-Pressure Analysis of Infinite-Conductivity Fractured Gas Wells Influenced by Non-Darcy Flow Effects
Authors: Nashawi Ibrahim Sami 
Published: December 2007

Abstract
Non-Darcy flow effects have long been recognized to have serious adverse impact on the performance of high-flow rate gas wells. These effects may mask the presence of fractures around the wellbore of naturally fractured reservoirs and may render the effective fracture conductivity and fracture half-length of hydraulically fractured wells much less than the designed parameters. Proper diagnosis of the post-fracture well test and good estimation of the fracture parameters are crucial for proper MHF treatment assessment and production forecast.
Even though the effects of non-Darcy flow have been identified in the field and properly acknowledged in the well testing literature, little has been done to improve the well test analysis results. This paper presents for the first time a semi-analytical equation that incorporates the effects of non-Darcy flow in the fracture. The proposed equation describes the flow of real gas under constant bottomhole-pressure condition which has the advantage of reducing the well test duration and minimizing the wellbore storage effects. A detailed investigation of the various parameters influencing the flow behavior of real gas in the fracture nearby the wellbore is also illustrated.
Design, Development, and Qualification of a Threaded and Coupled Connector for a Sour-Service-Compatible Completion and Workover Riser
Authors: Craig Gordon , Bailey Greg , Ethridge Roger , Byrne Wes 
Published: December 2007

Abstract
Offshore reserves are being exploited at ever increasing water depths. These fields require high pressure and thermal capabilities to develop and produce them. H2S is often a concern, if not initially, then after water injection wells are brought on line. The weight penalty of tubulars can be managed by utilizing elevated hardness, NACE MR-0175 compliant alloys such as API 5CT Grade T-95.
Riser connections often constist of forged and machined elements welded to pipe. This approach has been used for many riser types including production, completion/work-over and drilling. Although the connectors can be robust and fatigue resistant, welding restricts the use of T-95 and similar grades due the lack of weld procedures which maintain sulfide stress cracking resistance as determined by Method A.
Premium threaded and coupled type connections are widely used for high performance casing and other downhole applications. Historically, fatigue resistance is not required. Grant Prideco has initiated efforts to optimize the fatigue resistance of this type of connection. Threaded and coupled connections are presently in use in the Gulf of Mexico and other offshore locations as top tensioned production risers.
Their use as tool strings such as work-over risers and landing strings has been restricted by perceived sensitivity to galling and make/break capacity. Threaded and coupled connections used for casing and tubing applications are not typically optimized for the level of galling resistance required for tool strings. As detailed in this report, this type of connection can be enhanced to achieve the required make-break durability.
A large operator requested the development of a threaded and coupled connection for 7-5/8" x 71.60# (1.00" wall) T-95 riser pipe for use as a tool string capable for use in the installation, work-over, and flow test operation for subsea production systems. The string would be deployed in both open water and through the drilling riser, in 6,000 ft. of water from a moored, floating facility.
A design strategy was employed for this project which would optimize success while reducing development time and cost. Existing threaded and coupled designs were optimized for the application, which included the use as a tool string. An aggressive time-line was required, and met, for the design, development and qualification of this riser.
This paper describes the design, development and qualification process, offering insights into strategies and tactics employed to meet the functional design challenges, as well as the schedule requirements of this project.
The Evolution of Advanced Well Completions To Enhance Well Productivity and Recovery in Saudi Aramco's Offshore Fields
Authors: Sunbul A. H. , Hembling D. , Al Qudaihy D. S. , Al Harbi N. A. , Salerno G. 
Published: December 2007

Abstract
The Offshore sandstone reservoirs in Saudi Arabia are characterized by high production potential due to the nature of the reservoir, consisting of clean coarse sand with active bottom water aquifer and in some areas, a gas cap as drive mechanisms.
In recent years, horizontal wells have replaced conventional wells due to their improved deliverability and recovery efficiency. The initial completion method selected by Saudi Aramco for the horizontal wells was mainly cased hole cemented with selective perforation strategy. This completion method was troubled by non-uniform flow profiles, which drastically shortened the well production life reducing the benefit associated with the planned horizontal wells.
This paper will describe the concept of an innovative openhole completion strategy that has increased well productivity and recovery compared to past horizontal completion methods. The paper will show the evolution starting with the use of openhole completions completed with passive Inflow Control Devices (ICD) allowing production optimization by delivering uniform inflow along the entire horizontal section. The paper continues to discuss the benefits associated with the integration of the passive inflow control system with artificial lift (In situ gas lift and Electrical Submersible Pump (ESP) and finally reveals plans to couple passive inflow control with active intelligent well completion technology for multilateral wells. Actual field data will be presented to validate findings and support conclusions.
Constant-Pressure Analysis of Oil Wells Intercepted by Infinite-Conductivity Hydraulic Fracture Using Rate and Rate-Derivative Functions
Authors: Malallah Adel , Nashawi Ibrahim Sami , Algharaib Meshal 
Published: December 2007

Abstract
Wellbore storage effect can highly degrade conventional pressure buildup and drawdown tests data disturbing the formation characterization of the wellbore surrounding area. Constant bottomhole pressure tests will eliminate this pitfall and provide good reservoir describtion.
This paper applies direct synthesis technique for infinite conductivity fractured wells producing at constant bottomhole pressure from finite reservoirs. Without resolving to type-curve matching or regression procedures, this technique analyzes the log-log plot of the reciprocal rate and reciporocal rate derivative data to determine the fracture and reservovir parameters. These plots reveal the presence of straight lines corresponding to linear and pseuso-radial flow regimes; while the the boundary flow effect is detected by an exponential behavior. A 0.65 slope straight line describing the transition period between the pseudo-radial and the boundary effect flow regimes in rectangular systems is also presented. The distinct features of the straight lines' slopes and intersection points are used to calculate various reservoir and fracture parameters such as fracture half-length, reservoir permeability, skin factor, drainage area and shape factor. Equations corresponding to the points of intersections are very useful to verify the accuracy of the results obtained from the slopes of the different flow regimes.
A systematic step-by-step procedure illustrating the methodology of the proposed technique for the analysis of linear, pseudo-radial, pseudosteady state flow regimes is described. Detailed examples using different simulated cases are presented to show the applicability of the proposed method.
Step Change in Remote Exploration
Authors: Shafer Randall Scott 
Published: December 2007

Abstract
Remote Arctic onshore exploration can be very costly, frequently exceeding the cost of a deepwater Gulf of Mexico well. This paper reviews the reasons for these high costs and a possible combination of new proven technologies and rig designs to significantly reduce these costs
Logistics, mobilization, demobilization and a limited drilling season are factors that combine to cause high costs. Operation time requirements and the short drilling season normally results in a rig drilling one well per season.
A significant reduction in exploration final hole size is the primary driver in reducing costs as this leads to a major reduction in rig size. Downsizing does not limit well evaluation due to recent developments in downsizing evaluation equipment. The majority of the required information can be obtained with this finder well or "scratch and sniff' approach.
This downsizing allows the use of an innovative rig design; hybrid coil tubing drilling unit; that has significantly reduced mobilization and demobilization times. The reduction in drilling and mobilization/demobilization time can result in one rig drilling multiple wells in the drilling season.
Combining new technologies, such as casing drilling and coil tubing drilling, reduces drilling time and allows the hybrid coil tubing rig to drill deeper. Casing drilling and coil tubing drilling are areas where ConocoPhillips is an industry leader.
A significant reduction in exploration cost is predicted, estimated at 50%.