bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Predictive Tool for an Accurate Estimation of the Saturated Water Content of Sour Natural Gases
Authors: Bahadori A. , Vuthaluru H. B. , Jalili J. 
Published: July 2010

Abstract
Natural gas is an important source of primary energy which is saturated with water vapor from the reservoir, through production and processing and is a concern in transmission. Also the water content of sour natural gases is an important parameter in the design of facilities for the natural gas production, transmission, and processing. In this work, an easy-to-use predictive tool which is simpler than current available models and involves a fewer number of parameters, requiring less complicated and shorter computations, is formulated to arrive at an appropriate estimation of the saturated water content of acid gas mixtures up to 69000 kPa. With gases containing CO2, the CO2 must be converted to an "equivalent" H2S concentration. For purposes of this predictive tool, it is assumed that the CO2 will contribute 75% as much water to the gas mixture, on a molar basis, as H2S. The new developed predictive tool works for pressures ranging from 2900 to 69000 kPa and temperatures from 25 to 175°C. The correlation is formulated as a function of temperature and "equivalent" H2S concentration for pressures at 2100, 6900, 14000, 21000, 41000 and 69000 kPa (abs). Simple interpolation formula generalizes the correlation for wide range of pressures. Percent average absolute deviation of the proposed predictive tool is found to be around 2% demonstrating the excellent performance of proposed simple predictive tool and can be of immense practical value for the engineers and scientists to have a quick check on the water content of sour natural gases at various temperatures and pressures without performing any experimental measurements. In particular, gas process engineers would find the proposed approach to be user friendly involving no complex expressions with transparent calculations.
The Mechanism of Pressure Control Problem in High H2S/CO2 Gas Wells
Authors: Zhi Zhang , Jianhong Fu , Yuanhua Lin , Taihe Shi , Hongkang Fan , Bin Xia , Zhang Jincheng 
Published: July 2010

Abstract
Supercritical fluid refers to substancees above its critical temperature and critical pressure. Critical temperature of CO2 is 31.05°C and its critical pressure is 7.38MPa. Critical temperature of H2S is 100.45°C and critical pressure 9.00MPa. The special phase behavior of supercritical state is: Lower viscosity, great density and diffusion coefficient, good mobility, sound solubility and mass transfer behavior and especially sensible to the change of temperature and pressure around critical point. Phase change of supercritical CO2 and H2S will induce serious blowout during the course of drilling and production. In this paper, the reason of well blowout induced by phase change of supercritical CO2 and H2S is discussed proceeded with special phase character by the complex calculation of relevant samples. It is possible that CO2 and H2S in high acidic gas well is in the state of supercritical fluid. Well blowout will occur because the volume of CO2 and H2S in the annulus space is dramatically expanded in annulus space near well head owing to the phase transformation. It is of great importance to discover the kick and to measure the instant annulus flow of drilling fluid during the drilling process of high pressure and acidic gas well.
Efficiency in Cement Jobs for Fresh Water Formations Isolation During Plug and Abandonment in Canadon Seco Field, South Argentina
Authors: Graterol H. J. 
Published: July 2010

Abstract
In the San Jorge Basin, located in South Argentina, Well Plug and Abandonment (P&A) regulations include the guarantee of fresh water formations isolation from once productive formations. Cement Bond and Variable Density Logging (CBL/VDL) are recorded after a squeeze job to confirm cement integrity in the annulus, allowing protecting the most important fresh water formation in the basin: Patagoniano.
Historically, to isolate the Patagoniano multiples of costly squeeze jobs were done to achieve an appropriate result in the CBL/VDL. The main problem from this shallow formation is its high degree of fluid losses, most slurry is lost in these unconsolidated and high-permeability shallow sands (while pumping and during cure). Under this condition costs in the Canadon Seco Field for P&A were exceeded.
To overcome this problem, a review of previous results was done and many flaws were identified in the slurry physical characteristics and the used placement techniques. A new slurry and procedure was selected (after being laboratory tested) to be applied in the field; then a campaign of 14 wells was done using the selected slurry and following a general technique; cost/time reduction was drastic in comparison with previous P&A operations.
This paper presents the whole procedure for achieving these results and also includes details in each phase of testing/design and execution. Geological and mechanical features of the wells are shown, as well as a description of the new technique / slurry (including concepts) and the obtained field results.
Synergetic Use of Cluster Analysis and Artificial Intelligence Techniques to Improve Reservoir Upscaling
Authors: Rezazadeh Mehrdad , Choobary Saeedeh Gharib 
Published: July 2010

Abstract
Upscaling in many cases is essential to reduce the computational time but there is always a disparity between the upscaled model behavior and fine geological model behavior. Up to now there has been an immense effort to reach an upscaling method which is in the most similarity with the fine geological model.
This paper presents a novel implementation of synthesizing statistical tools and intelligent techniques. Statistical tools such as cluster analysis are widely used in order to process multivariate data. It is an integrated approach for petrophysical characterisation of the well data and it can be successfully applied globally to both clastic and carbonate reservoirs with use of logs and core data to define petrofacies. Artificial Neural Networks (ANN) mimics biological information processing mechanisms. They are typically designed to perform a nonlinear mapping from a set of inputs to a set of outputs.
In this paper we used artificial neural network to make modern algorithm for cluster analysis, then by use of this algorithm we make state-of-the-art software for cluster analysis. By this procedure not only computational time is reduced but also the resemblance of upscaled model behavior to the real reservoir geological model is improved.
The procedure and its application in synthesizing cluster analysis and Artificial Neural Networks is demonstrated by a case study.
Strategies for Removal of Formate Brine-Based Drill in Fluid (DIF) Filtercake in Gravel-Packed Completions: A Laboratory Evaluation
Authors: Salgaonkar Lalit , Ali Razien , Danait Achala , Salahudin Sharifudin 
Published: July 2010

Abstract
Formate brines and drilling fluids were primarily developed for high pressure drilling and completion applications. This completion fluid system is now being employed in more benign pressure environments and also to drill and complete formations with specific properties. This was the case where a potassium formate brine with 1.25 specific gravity (S.G.) was specified as the base fluid for the drill-in fluid (DIF) as well as completion brine for several openhole completions requiring gravel packing in offshore Brunei. The DIF used to drill the open hole deposits a protective filtercake on the borehole wall that is typically removed by means of a suitable removal system, enabling undamaged production.
Openhole filtercake breaker systems that are typically employed range from mineral and organic acids, which aggressively attack the filtercake and result in an incomplete cake removal, to ortho-esters, which hydrolyze in the brine and lead to the formation of a delayed acid, which has proven more efficient. The ortho-esters are mixed in the base brine and placed inside the open hole or gravel pack and allowed to react over time.
Formate brines, however, have proven to be poor base fluids for the ortho-esters because of their inherently high pH. A laboratory evaluation was conducted to address this problem. The tests showed that these ortho-ester-based systems, when mixed in a potassium chloride or sodium-bromide brine system, can be employed to break the formate-based DIF filtercake. A chelant-based breaker system, however, provides the most efficient cleanup with the necessary delay. This paper addresses the challenges and details of the laboratory testing performed to arrive at an optimized chelant-based delayed-breaker system in formate brine for removal of formate-based filtercakes. The paper also presents results of the performance of the ortho-ester system.
Mechanism of Well Deviation in Air Drilling and Its Control
Authors: Zhao Zengxin , Gao Deli , Zheng Deshuai 
Published: July 2010

Abstract
Combined with actual air drilling practices and data in western China, mechanical behavior of three different BHA used in actual air drilling was investigated. Bit side force and bit tilt angle of those three BHA both in air drilling and mud drilling were calculated and compared. Analysis results indicated that the bit side force and the bit tilt angle in air drilling is greater than that of in mud drilling due to more deformation of BHA. The fundamental reason of difficulty to control well deviation is because of the great formation anisotropic index and formation dip in air drilling. Some deviation control measures are recommended including the combination of air percussion hammer or air motor and pendulum assembly.
Holistic Automated Workflows for Reservoir and Production Optimization
Authors: Carvajal G. A. , Toro M. , Szatny M. , Robinson G. , Estrada J. 
Published: July 2010

Abstract
The optimization process in the oil industry requires a number of technical applications as well as significant manpower, expertise, and skills to develop robust reservoir and production engineering workflows. Several studies have reported that up to 70% of an engineer&apos;s time is spent in gathering, formatting, translating, and parsing data among applications.
Often, engineers are focused on isolated problems and deliver results that are optimized for that element of study. The optimization process frequently involves time-consuming iterations of input variables building output profiles, from which engineers will choose the optimum result. This optimized output data is then taken to the next step in the chain to optimize the subsequent study. These intermittent optimization choices may not deliver suitable input parameters on suboptimal output of the subsequent analyses. Because these sensitivities magnify through the optimization processes, ultimate recovery profiles and field economics are often suboptimal. Even with today&apos;s highly integrated databases and enhanced computing power, the traditional working processes will deliver suboptimal outputs.
This paper discusses new toolkits that can model a full chain of application driven data manipulations to assess the ultimate economic effect of engineering decisions such that the best system-wide (holistic) choices can be exploited; the whole of the system is more than the sum of its parts. The holistically optimum result produces the practical natural optimum of the actual operational process. We will demonstrate how holistic optimization processes can greatly enhance workflows for production and reservoir management, fracture design, water conformance, and field development planning.
Design and Performance Research of A Unique Deepwater Cement Slurry
Authors: Wang Chengwen , Wang Ruihe , Bu Yuhuan , Zhou Weidong 
Published: July 2010

Abstract
Deepwater region has been an area of intense interest in recent years, due to the hydrocarbon resources in deepwater areas are very captivating for oil companies. Unfortunately, in deepwater environment, where the water depth is greater than 500 m, faced with some new problems such as low temperature, weak formations, shallow water/gas flow, environmental protection issues and high rig rates of deepwater rigs.
Compared with conventional cementing, deepwater cementing is required to have short thickening time, a fast transition from liquid to solid, rapid development of compressive sthrenth and environmental friendly. Conventional cement slurries and low density cement slurries are usually taking a long time to set and can't allow significant compressive strength development at such low temperature. In addition, conventional cement additives are often environmentally unacceptable subject to more stringent environmental regulations. Therefore, it is stringent to design environmental friendly low density cement slurry to overcoming these challenges during deepwater cementing.
As these deepwater cementing problems are concerned, a new deepwater cement DWC, mainly combining the sulfoaluminate cement and class G oil well cement, was designed for the first time. And, various environmental friendly additives, including cement dispersant, fluid loss control agent and accelerator, were developed. Finally, a unique low density deepwater cement slurry was developed.
Laboratory tests show that the low density slurries has exhibited no free fluid, excellent fluid loss control, right-angle-set, short time of wait-on-time at low temperature, and a shortened transition time of static gel strength. The slurries can be simply prepared, conveniently implemented in field and be composed of environmentally friendly additives. Results presented in this paper should help resolving problems in deepwater cementing.
Advantages of Inflatable Packer Technology for Temporary or Permanent Well Abandonment in the Gulf of Mexico
Authors: Vaucher David , Brooks Robert 
Published: July 2010

Abstract
With so many wells operated in the Gulf of Mexico, one would think that the process of eventually abandoning these wells temporarily (during hurricane season), or permanently plugging and abandoning (P&A) them is by now more routine. Certainly, there are years worth of procedures and case studies on the subject, yet there are always "special cases" that require more specialized planning and equipment. For instance, toppled rigs present the challenge of "kinked" tubing, while other wells have several tubing or casing strings through which a plug must pass before setting in a larger diameter opening.
For these non-routine operations, inflatable packer technology presents several significant advantages: small restriction clearances and high expansion ratios as compared to traditional mechanical bridge plugs. Additionally, inflatable plugs are incredibly versatile in that they can be conveyed to depth using either coil tubing, threaded tubing, even slickline and wireline. Finally, inflatable plugs do cover a wide range of hole conditions (temperature, washouts, etc), and are therefore robust enough for most well decommissioning jobs.
This paper will present the unique advantages of inflatable packer technology in these decommissioning operations and will illustrate these advantages using job examples and case studies. The examples and cases used will be limited to the Gulf of Mexico, yet the advantages of these technologies can be applied to any well worldwide.
Sour Serviceability of Higher-Strength Coiled Tubing: Final Results
Authors: Padron T. 
Published: July 2010

Abstract
As earlier as 1999, the need for industry guidelines regarding the use of coiled tubing (CT) in sour wells was recognized2. Small scale standard NACE tests (i.e. proof ring, C-ring, double cantilever beam, and slow strain rate tests) have been performed to evaluate the behaviour of CT materials in sour environments1,3,4,5. Although these tests evaluate the crack resistance properties of the material in sour conditions, they do not give data regarding the low-cycle fatigue performance of CT after sour exposure that could be used for CT strings management in real operating conditions.
By 2003, uniaxial low-cycle corrosion fatigue tests of short full body CT samples were used to evaluate the sour performance of 70 and 80 grade materials5. These tests, although they considered fatigue performance, were based on uniaxial reversing loads rather than reversing bending strains, which is what occurs in CT operations. In addition to this, the need of high-strength CT materials (i.e. 90 grade and up) in sour wells required additional knowledge regarding their sour performance.
By the end of 2004, a joint industry project (JIP) among ExxonMobil Development Company, Shell Canada Limited and BJ Services Company was initiated to investigate the serviceability of high-strength CT in sour environments, with the main emphasis on the measurement of low-cycle bending-fatigue life after sour exposure using full body CT samples. Some of the early results of this project were included in a previous paper6.
The present paper summarizes more than 4 years of laboratory testing aimed to establish the effect of sour exposure on the low-cycle fatigue life of CT materials. Other aspects related with the possible CT degradation from sour exposure are also included, such as the effect of different sour environments severities, performance of anti-cracking (H2S) inhibitors, effect of pre-fatigue, butt-welds and bias welds performance, and tensile strength integrity. The results have led to changes in the current operating procedures regarding CT strings management and CT material selection criteria for sour service.
Experimental Study on CO2 Monitoring and Saturation with Combined P-wave Velocity and Resistivity
Authors: Kim Jongwook , Xue Ziqiu , Matsuoka Toshifumi 
Published: July 2010

Abstract
As a part of basic studies with the purpose of better understanding to estimate the saturation of stored carbon dioxide (CO2) with seismic velocity and resistivity, laboratory experiment has been conducted to monitor combined P-wave velocity and resistivity simultaneously in porous sandstone during CO2 injection process. Experiments were conducted by simulating the reservoir condition with high temperature and high pressure in depth of about 1000m or more. Supercritical CO2 (10MPa, 40°C) was injected into water-saturated sandstone. The results showed that resistivity increased monotonously throughout the injection period, and P-wave velocity and amplitude decreased drastically after starting injection of supercritical CO2. CO2 saturations estimated by both Resistivity Index (RI) and Gassmann fluid-substitution equations based on P-wave velocity and resistivity were very matched with CO2 saturation from replaced brine in a sample. By comparing velocity-saturation relation with resistivity-saturation relation estimated by Gassmann and RI model, P-wave velocity becomes less sensitive when CO2 saturation is over about 20%, while resistivity kept increasing with increase of CO2 saturation. Resistivity can complement effectively the difficulty of P-wave velocity on quantifying CO2 saturation from suggested equations.
Fiscal Regimes in a Volatile Oil Price Era: What Options Exist for Balancing the Interest of the Resource Country and Investor Company?
Authors: Onyeukwu Humphrey 
Published: July 2010

Abstract
Volatility in oil prices is a reflection of the common characteristic of the commodity-oil. This is linked to a high uncertainty associated with resource development, and the high specificity of investment along the entire energy value chain. Oil price volatility has become a recurring dilemma in an energy market mired in cyclical trends of pricing shocks. The International Energy Agency (IEA) in its World Energy Outlook 2008 predicted an increasing demand at the rate of 1.6%/y on average between 2006 and 2030. As a result, issues of fiscal terms re-negotiations and rent-seeking will shape the relationship between producing countries and investor companies. A major corollary of this instability in oil prices is a renewed battle for rent between host governments and investors. This in effect would engender a shift in balance of the applicable petroleum fiscal regimes.
The challenge of a fiscal policy in a volatile price oil era is ensuring a high share of value is secured for the Government. At the same time, the fiscal policy strives to encourage the exploration of these valuable resources without harming the commercial interest of the oil companies. Price volatility fundamentally alters the sharing formula; it is therefore imperative for a correct balance to be achieved between the competing state interests and the oil companies. The question becomes how equilibrium can be achieved in a petroleum fiscal system design, which guarantees suitable government take and avoids the negative effect of instability and re-negotiation of fiscal terms.
The objective of this paper is to analyse the options available to resource countries in securing appropriate economic rent and safeguard the interest of the investors in the face of pricing volatility. The paper will adopt both analytical and descriptive approaches in articulating these issues.
Corrosion Mitigation - The Corrosion Engineers Options
Authors: Winning I. G. , Taylor Andrew , Ronceray Martin 
Published: July 2010

Abstract
With focus on design of new facilities in hostile environments and re-lifing of aging assets the requirement of corrosion engineers to be able to make the correct decision on the corrosion mitigation methods is key to the continued economical supply of oil and gas. Although many engineers have a broad focus on the options, the techniques available are sometimes disparate and may not be encompassed under one discipline. The development of an overall corrosion mitigation approach and the need to look at total life cycle costs are therefore important for a project to achieve design life or extend the operating life of existing assets. The various subjects including material selection, external and internal corrosion mitigation will be discussed and also how all the possible processes can be bought together into an effective corrosion management system for the long term integrity of the asset.