bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Study on the Efficiency of Cuttings Carrying with Supercritical CO2
Authors: Li Gensheng , Haizhu Wang , Zhonghou Shen , Song Xianzhi , Guanwei Tang , Xinjuan Hou 
Published: July 2012

Abstract
Supercritical carbon dioxide (SC-CO2) has the characteristics of high density, low viscosity and high diffusivity, and higher penetration rate can be achieved with SC-CO2. But the law of cuttings carrying is not clear, in order to make clear the influence of pump displacement, well incline, cuttings diameter, wellbore temperature and pressure on cuttings carrying efficiency, the laboratory experiments was carried out to simulate the cuttings carrying with SC-CO2 in annulus. The result shows that the cuttings carrying efficiency decreases when pump displacement decreases and cuttings diameter increases, and it decreases with the increasing of well incline at first, and then increases. Wellbore temperature and pressure have much more influence on cuttings carrying efficiency, and it decreases when the wellbore pressure increases, if keeping the wellbore temperature and pump displacement in constant; and it increases when wellbore temperature increases, if keeping the wellbore pressure and pump displacement in constant. So the wellbore temperature can be adjusted to compensate the cuttings carrying efficiency's changes caused by pressure changes, and the excess annulus velocity should be in consideration to avoid erosion of casing, drilling pipe and other down hole tools.
Successful Implementation of Latest Generation of Double Shoulder Connection Technology in Fast Slimhole Drilling - A Review after Broad Adoption in the Gulf of Thailand
Authors: Plessis Guillaume , Brock Jim , Wood Jeff 
Published: July 2012

Abstract
In 2010, Chevron Thailand successfully conducted a unique comparative field test involving two strings of drill pipe, one featuring a new 3rd generation double shoulder connection (3rd Gen DSC) against another with the previous generation connection (2nd Gen DSC). Both strings were used to drill off the same offshore platform with all parameters being equal besides the drill pipe connection selection. This test was required to gauge a possible solution to the operator's need for higher drilling torque in the challenging fast rotary drilling of the slimhole production interval.
The evaluated 3rd Gen DSC was originally developed and introduced to allow drilling always more challenging wells. It was designed to achieve a set of performances, which exceed the capability of the successful 2nd Gen DSC for torque and hydraulics with an enhanced fatigue resistance. One of the particular design priorities was to allow for fast makeup and breakout through the use of a new feature to drill pipe; a double start thread.
Results of this field trial were gathered in a previous paper that shows actual time saving in running speed, which is of interest to Chevron, initial trend seen in the lower number of connection needing repairs and evaluation of the cost saving for adopting the new technology on all rigs drilling for the operator. Based on this initial set of data, Chevron decided to switch to the 3rd Gen DSC for the 4 in. drill pipe used in slimhole drilling.
This new paper will briefly summarize the result of previously presented material but will focus on the actual field experience with the new technology deployed on three drilling rigs for more than six months now. Special emphasis will be put on evaluating the connection ruggedness through results found in the inspection of the equipment, which was hard to evaluate on the initial short time trial.
BHA Modeling Coupled with High Frequency Downhole Vibration Data Provides Unique Solution to Inconsistent Drilling Performance in South Iraq Oilfield
Authors: Teasdale Paul , Chafai Ridha , Saeed Ahmed , Hussain Muneeb , Perez Daniel , Sun Xueying , Yingguang Li 
Published: July 2012

Abstract
Drilling activity has increased rapidly in Iraq over the last few years. With the lack of reliable downhole data to develop a solid strategy to optimize drilling operations, the drilling performance has been inconsistent with frequent failures of drill stem components. Without the aid of quality downhole data it is very difficult to identify the root cause of these failures, and more importantly, provide a means to identify a solution to improve performance.
This paper showcases a project in South Iraq where modeling of the drilling BHA's using a unique Finite Element Analysis software package identified critical natural frequencies of the drillstring. The integration of high frequency downhole vibration data collected in multiple positions of the string provided the evidence to validate the vibration road map delivered by the BHA analysis.
The objective of the project was to identify the primary vibration mode, evaluate the vibrations severity, cause and source in the 12¼" vertical section and provide recommendations to achieve performance improvement through controlled step changes in bit & BHA design, drilling parameters and operational procedures. The pre-well BHA model analysis identified that the premature bit failure was a direct result of lateral vibrations induced by operating in a critical lateral harmonic zone. This was validated with the downhole vibration data.
A well-established optimization process including expert detailed analysis of the high frequency downhole vibration data provided a clear understanding of the relationship between the pre-well BHA model, the drilling parameters planed and the associated downhole drilling dynamics.
The impact on performance was clear. Implementation of the new recommended drilling parameters derived from the BHA analysis applied to the same bit and BHA used in Well #1 resulted on a 26% increase in drilling performance in well 2.
Evaluation of a New Environmentally Friendly Treatment to Remove Mn3O4 Filter Cake
Authors: Elkatatny S. M. , Al Moajil A. , Nasr-El-Din H. A. 
Published: July 2012

Abstract
Manganese tetraoxide is used as a weighting material in drilling deep wells (&gt; 90 lb/ft3). Removal of the filter cake that contains Mn3O4 is a difficult task. This is mainly because Mn3O4 is a strong oxidizing agent.
Extensive lab work was done to: 1) study the reaction of glycolic acid with Mn3O4 particles (D50 =1 μm) as a function of time at 190°F in a batch reactor, 2) examine the solubility of the filter cake using a modified HP/HT filter press, 3) determine the compatibility and thermal stability of cleaning fluids with α-amylase using an HP/HT visual cell, 4) characterize the filter cake using computer tomography (CT), and 5) assess the retained permeability of limestone and sandstone cores.
The results following the removal of the filter cake showed that 4 wt% glycolic acid (4 g Mn3O4 to 200 ml acid solution) dissolved 75 wt% of Mn3O4 particles at 190°F. Glycolic acid (5 wt%) had a removal efficiency of 85 to 90% of manganese tetraoxide-based filter cake after 20 hrs soaking time. The retained permeability was 100% for the Indiana limestone core and 125% for the Berea sandstone cores. CT results showed that glycolic acid was able to stimulate the cores and no formation damage was observed.
Three-Dimensional Modeling of Casing and Cement Sheath Behavior in Layered, Nonhomogeneous Formations
Authors: Shen Z. , Beck F. E. 
Published: July 2012

Abstract
Shale is identified as one of the main factors strongly impacting the distribution of stress in the casing and cement sheath system. The risk of radial cracking induced by thermal stress should not be overemphasized, and it highly depends on fluid temperature in the wellbore and fluid circulation time. Long-term casing and cement integrity is fundamental to the successful and economical development of high-pressure, high-temperature (HPHT) hydrocarbon reservoirs. Casing failure and cement debonding as a result of extreme downhole conditions have been recorded worldwide. Research on casing and cement sheath failure in the past few years has been conducted assuming either plain strain or axisymmetric strain in a homogeneous formation. It usually underestimates casing deformation and cement sheath failure caused by the effect of a nonhomogeneous formation.
We present a three-dimensional (3D) finite element model consisting of five formation layers to simulate casing and cement sheath mechanical response in interbedded, nonhomogeneous formations. The radial stress of cement sheath is found to be highly variable and affected by the contrast in Young's moduli in the different formation layers. Maximum stress concentration is predicted in the casing-cement sheath confined by sandstone. Application of this research is useful for casing design, as well as evaluation of downhole failures.
Innovative Casing Exit Milling System Optimized Using Drillstring Dynamics Simulation for Efficient Multilateral Completions
Authors: Guidry Christopher W. , Thomas Reena 
Published: July 2012

Abstract
A typical method of creating casing exit windows for multilateral completions includes using tool strings comprised of mills for traversing whipstocks and creating elliptically shaped windows. This paper describes an innovative casing exit milling bottomhole assembly (BHA) and the method by which its design and predicted performance were optimized using inhouse-created drillstring dynamics finite element analysis (FEA) software.
Relatively longer casing exit windows are required to be generated for subsequent passage of contemporary drilling equipment. Sophisticated simulation technology is being used in designing the milling BHAs to create these longer exits. Paramount to generating a long window is maintaining sufficient restraining forces on the bottom-most mill to keep the mill tracking the full ramp length. Preferably, the BHA is designed so that the bottom-most mill can traverse against the entire ramp, and then deviate away from the ramp to avoid undesirable re-entry into the exited wellbore. The challenge is to optimize the milling BHA's endured contact forces so that its fatigue life is increased.
The aforementioned analytical tool helped in designing the milling BHA so that its operational bending stresses were reduced and its fatigue life was increased. Purposefully designed shapes and placements of the BHA's bladed cutting sections provided a favorable distribution of restraining forces, thus enabling an optimal-length casing exit window.
As directional drilling assemblies continue to be made longer and stiffer, there is an increased significance of using simulation tools to design milling BHAs. These newly designed BHAs will continue to be enhanced to maximize window length for improved ingress and egress of rotary steerable drilling BHAs. Extensive analysis, qualification testing, and field trials were performed on these systems. Case histories describing operational results will be shared and discussed during the paper presentation.
Expanding Surfactant Technology to Enable Project Successes
Authors: Jones Tom A. , Quintero Lirio , Toro Carlos , Ullauri Patricia , Guerra Cesar 
Published: July 2012

Abstract
Surfactants systems have been used in oil well drilling and completion fluids for several decades and have been used for numerous applications, including emulsification of brine for invert emulsion fluids, emulsion prevention in completion fluids, wellbore clean-up in spacer trains, flowback enhancement in drill-in fluids, etc.
In recent years, the use of specialized designer surfactant blends to remove formation damage and dramatically improve production in cased hole and open hole completed wells has prompted field personnel to expand the range of target applications of this technology.
The aforementioned specialized surfactant blends have several unique functional characteristics that make them ideal for multiple uses in the field. Generally, these systems solubilize oil, remove oil from surfaces, remove emulsions, water-wet and disperse solids, reduce interfacial tension and mobilize in-situ fluids.
With a full understanding of the mechanistic ways that these surfactant blends function under downhole conditions and when confronted with various operational issues in the field, this technology was successfully used to free stuck pipe, to free blocked completion screens of heavy oil sediments and to prepare a well for water injection.
This paper presents some of the technology associated with specialized designer surfactant blends and the case studies where the technology was applied in the field to enable project successes.
Innovation of Coal Seam Gas Well-Construction Process in Australia: Lessons Learned, Successful Practices, Areas of Improvement
Authors: Bennett Thomas 
Published: July 2012

Abstract
From by-product to multi-billion dollar industry, the Coal Seam Gas (CSG) industry in Australia has recently experienced rapid growth however is still facing many challenges. The Australian CSG industry is approaching a cross-road; the transition from a Domestic Gas business to exporting the CSG resources, requiring a significant scale up of current operations. Well design innovation is one of the necessary levers to maximize the full potential of CSG as a competitive energy resource. This paper focuses on the technical challenges associated with driving continuous improvement in drilling and completion practices as a key success factor for competitive performance.
The growth expected in the CSG industry over the next few years will be rapid. Arrow Energy plans to increase its production from 150 TJ/day in 2012 to 1350 TJ/day in 2018. This will require increases in drilling performance. Much of the early success will likely be obtained from the transfer of benchmark practices, where relevant, from the more mature global oil and gas industry - rather than from true CSG innovation. However, given the lower cost margins and economics of CSG, this knowledge transfer will need to be coupled with innovative application and new approaches.
This paper will discuss the importance of innovation in basis of well design as a lever to drive improvements in CSG in Australia and outline some of the key areas that Arrow Energy is focusing on to achieve this, including:
The need for fit for purpose rigs to meet well design criteria and well safety requirements. Standardization of well designs and equipment aligned to local government regulations and American Petroleum Institute (API) regulations. Vendor alignment and incentivized performance to meet company targets. Problems associated with innovation and difficulties of implementation in short time frames as well as the application of lessons learned from trials. Well design evolution and optimization of gas recovery. The importance of adopting a culture of learning and flexibility to implement changes as design standards progress.
Research and Application of Nanoscale Emulsion Lubricating Material for Drilling Fluid in Daqing Oil Field
Authors: Yang Zhiguang , Liu Yonggui , Zhao Xiaozhu , Song Tao , Yan Jing , Jia Weijun 
Published: July 2012

Abstract
In Daqing Oil Field of China, to solve the problem of low drilling rate, high friction drag, complex accidents(such as pipe sticking) and long non-penetration time, a nanoscale emulsion lubricating material has been developed. Its nanoscale particles can adhere to the wall and the string directionally and then form the dense lubricant film and protective film. It can improve the lubricity, make wall wettability reversal, inhibit the clay swelling, plug the micro-fracture and stabilize the wall.
In the process of application in 60 wells in Daqing Oil Field of China, this material solved the problems of high friction drag in drilling operation, reduced the non-penetration time due to moving drilling tools caused by high friction drag, decreased the pipe-sticking risk and complex accident rate, improved the drilling rate. The average drilling cycle is reduced by three to five days in shallow horizontal wells. It can avoid complex accidents (hole collapse, pipe sticking, etc), ensure the operation successful and increase the drilling rate obviously in deep horizontal wells.
It can improve the lubricity and inhibitive ability of drilling fluid and replace the mineral oil, reduce the circulation time of geologic control, increase the drill-meeting rate of oil sandstone and is favor of discovery of reservoir.
It solved the problem of low drilling rate, high backing pressure and high complex accident rate, decreased environment pollution, ensured the hole stability and can be popularized in unconventional wells, including horizontal wells, directional wells, etc.
Abundance dynamics of mites (Acari) in the peatland of ‘Linie’ Nature Reserve, with particular reference to the Gamasida
Authors: Kaczmarek Sławomir , Faleńczyk-Koziróg Katarzyna , Marquardt Tomasz 
Published: July 2012

Abundance dynamics of mites (Acari) in the peatland of ‘Linie’ Nature Reserve, with particular reference to the Gamasida
The research was conducted in ‘Linie’ Nature Reserve within the Lower Vistula Valley Land-scape Park in central Poland. We analysed the annual abundance dynamics of soil mites as well as changes in gamasid community parameters (abundance, age structure, species diversity). Density changes among the juvenile Gamasida greatly influenced the annual abundance dynamics of mites belonging to that order. Alternations in the abundance dynamics of Platyseius italicus and Zercon zelawaiensis were connected to the appearance of males as well as the density increase in juvenile specimens of those species.
Hydrozetes species (Acari, Oribatida) at bog ponds and pools in the Tatra National Park and Orawa-Nowy Targ Basin (Kotlina Orawsko-Nowotarska) in southern Poland
Authors: Mistrzak Marcin , Seniczak Anna , Seniczak Stanisław 
Published: July 2012

Hydrozetes species (Acari, Oribatida) at bog ponds and pools in the Tatra National Park and Orawa-Nowy Targ Basin (Kotlina Orawsko-Nowotarska) in southern Poland
The Hydrozetes fauna was investigated at the edges of 4 ponds and pools with acid water in southern Poland. Mites of this genus achieved the highest mean abundance (6x104 ind./m2) at a pond in the Tatra National Park (Staw Toporowy Niżni; pH = 3.9; 1089 m a.s.l.). H. confervae dominated there (98%), accompanied by H. octosetosus and H. lacustris. The same species were also present at a nearby pond (Staw Toporowy Wyżni; pH 3.9; 1120 m a.s.l.), but in significantly lower numbers. In the bogs of the Orawa-Nowy Targ Basin, at the edge of pool in Kaczmarka (pH 3.6; 650 m a.s.l.), H. lacustris and H. octosetosus were present, and the former species dominated (73%). The latter species is interesting, because it was not recorded in Europe until recently. At the other pool, in Łysa Puścizna (pH 4.5; 650 m a.s.l.), only H. lacustris was present. The lower abundance and species richness of Hydrozetes at the bog pools in the Orawa-Nowy-Targ Basin, in comparison to the Tatra National Park, was probably caused by poorer water conditions, due to more advanced succession, peat exploitation and disturbed water conditions in the Basin.
Ecology of Hydrozetes Berlese, 1902 (Acari, Oribatida) at various water bodies near Bydgoszcz (northern Poland)
Authors: Seniczak Anna 
Published: July 2012

Ecology of Hydrozetes Berlese, 1902 (Acari, Oribatida) at various water bodies near Bydgoszcz (northern Poland)
Mites of the genus Hydrozetes Berlese, 1902 are abundant and important in wet habitats and can be useful in palaeoecological studies and bioindication. However, due to problems with their identification, there is still a limited knowledge on their ecology. In this study, 5 Hydrozetes species have been investigated. The most abundant was H. lemnae (about 121 000 ind./m2), which constituted 76% of the total Oribatida at a pond shore in the Botanical Garden in Myślęcinek in Bydgoszcz. Its population density was lower in duckweed and filamentous algae on the water surface of the same pond. This species was found also in several other bodies of water, varying in water quality, but it preferred neutral pH. Hydrozetes thienemanni had a narrower ecological tolerance and was restricted only to a forest pond with neutral pH in Pruszcz, where it dominated among the Oribatida. Three other species - H. lacustris, H. octosetosus, and H. longisetosus - were found only in acid water. The last mentioned species was absent from the peat pond in Bagno Chlebowo Nature Reserve, with a high concentration of sulphur and worse oxygen conditions, but that site was suitable for H. lacustris.
Morphological abnormalities in mites of the genera Zercon and Prozercon (Acari: Gamasina) collected near caves: preliminary results
Authors: Barczyk Gabriela , Madej Grażyna 
Published: July 2012

Morphological abnormalities in mites of the genera Zercon and Prozercon (Acari: Gamasina) collected near caves: preliminary results
Eleven mites of the genera Zercon C. L. Koch, 1836 and Prozercon Sellnick, 1943 with various morphological deviations (changes in chaetotaxy) are described. The mites were collected from the natural environment, near limestone caves in the Kraków-Częstochowa Upland (Wyżyna Krakowsko-Częstochowska) in southern Poland.
Analysis of Partition Coefficients of Ternary Liquid-Liquid Equilibrium Systems and Finding Consistency Using Uniquac Model
Authors: Islam Akand , Zavvadi Anand , Kabadi Vinayak 
Published: July 2012

Analysis of Partition Coefficients of Ternary Liquid-Liquid Equilibrium Systems and Finding Consistency Using Uniquac Model
The objective of this study is to investigate the change in partition coefficient with a change in the concentration of the solute in a liquid system consisting of two relatively immiscible solvents. To investigate the changes in the partition coefficients, the data of the partition coefficients at infinite dilution and the ternary Liquid-Liquid Equilibrium (LLE) data at finite concentrations of the solute should be consistent. In this study, 29 ternary systems that are found in literature and for which the partition coefficients at infinite dilution and the ternary LLE data cannot be predicted accurately by the universal quasi-chemical (UNIQUAC) model are identified. On the basis of this model, some consistent and inconsistent ternary systems are introduced. Three inconsistent systems, namely hexane-butanol-water, CCl4 (carbon tetrachloride)-PA (propanoic acid)-water, and hexane-PA-water, are chosen for detailed analysis in this study. The UNIQUAC activity coefficient model is used to represent these data over a range of concentrations. The results show large errors, exhibiting the inability of this model to correlate the data. Furthermore, some ternary systems in which cross behavior of solutes between two phases observed are identified.
Brownian dynamics for calculation of the single fiber deposition efficiency of submicron particles
Authors: Sztuk Ewa , Przekop Rafał , Gradoń Leon 
Published: July 2012

Brownian dynamics for calculation of the single fiber deposition efficiency of submicron particles
The motion of submicron particles involves the deterministic terms resulting from the aerodynamic convection and/or electrostatic attraction, and the stochastic term from the thermal displacement of particles. The Langevin equation describes such behavior. The Brownian dynamics algorithm was used for integration of the Langevin equation for the calculation of the single fiber deposition efficiency. Additionally the deterministic and stochastic of the particle motion were derived, using the Lagrangian and Eulerian approaches of particle movement and balance, for the calculation of the single fiber deposition efficiency due to both mechanisms separately. Combination of the obtained results allows us for calculation of the coupling effect of inertia and interception with the Brownian diffusion in a form of correlation. The results of calculation show that the omitting of the coupling effect of particular mechanism and using the simple additive rule for determination of the single fiber deposition efficiency introduces significant error, especially for particles with diameter below 300 nm.