bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ongoing Development of Cementing Practices and Technologies for Kuwait Oil Company’s Deep HPHT Exploration and Gas Wells – Case History
Authors: Al-Saeedi M. J. , Al-Enezi D.. , Al-Mudhaf M. N. , Modak T.. , McKinnell D. C. 
Published: February 2011

Abstract
Exploration activities in the state of Kuwait have been focused on the search for high quality oil from the Jurassic formations and gas in the Triassic/Permian series. The wells drilled to these prospects are very challenging because of HPHT conditions, large casing sizes, oil base mud, presence of high levels H2S/CO2 and narrow pore/fracture pressure window. As such, the cementing of the deep strings in these wells has been extremely challenging. Over the last eight years a concentrated effort has been made to introduce new technologies and materials to improve the cementing practices both from operational and safety aspects.
In 2003 the success ratio for deep cementations was highly variable. KOC along with one of their cementing service providers worked on a series of changes to practices and materials with the aim of improving job quality with high repeatability. This was based primarily on the technologies being developed in HPHT wells around the globe and especially in the North Sea and it resulted in a notable improvement in cementing performance.
Technologies and practices that had been developed include spacer technology, application of synthetic retarders, fluid loss and anti-gas migration additive improvements, development of fine grained weighting additives, use of HPHT rheometers, systematic product control, minimizing handling and safer mixing practices at the well site.
This paper will discuss the application of these technologies, materials and practices over an eight year period as a case history to illustrate the improvements made in achieving consistent cement quality and final slurry placement for the deep casing and liner strings and will conclude with recommendations and lessons learnt during this process.
Stimulation Combined with Hydrajetting Technology Achieves Excellent Results in Gas Producers in Saudi Arabia: Field Cases
Authors: Alabbad E. A. , Solares J. R. 
Published: February 2011

Abstract
As a growing number of gas producers are drilled in deeper and tighter formations in Ghawar field in Saudi Arabia, and as wellbore accessibility becomes more challenging — in high-angle and horizontal wells in particular — effective stimulation is harder to achieve. Because the utilization of conventional perforating and stimulation methods has not achieved the targeted production rates, a different approach which combines hydrajetting techniques with other stimulation methods has been successfully field tested with excellent results. Hydrajetting technology is used to create sufficient slots along the wellbore wall to facilitate fluid entry, and provide an adequate communication channel from and into the reservoir. The use of the technology in different applications has overcome a number of the previously encountered challenges and allowed effective stimulation in a significant number of gas producers. This paper presents an overview of hydrajetting technology, provides details about the methodology being used, and shares results from three recent applications.
Development of Techniques to Integrate Hydraulic Fracturing Design and Reservoir Simulation Technologies — Application to Forecast Production of Stimulated Wells in Unconventional Gas Reservoirs
Authors: Fazelipour Waleed 
Published: February 2011

AbstractUnconventional gas plays are becoming of increasing interest worldwide, as E&P companies search for alternative hydrocarbon resources. Successful E&P operators are increasingly using hydraulic fracturing to maximize production. Multistage hydraulic fracturing, the key technology to enhanced well performance, creates stimulated reservoir volumes (SRV) surrounding the stages. SRV are the main contributors to higher production profiles. Hence, it is very desirable for the E&P industry to evaluate and optimize the hydraulic-fracturing treatment to maximize profitability.One of the best technologies that can help understand the dynamics of unconventional reservoirs to optimize the wellbore placement and improve well productivity is reservoir modeling and simulation. Main challenges to dynamically model stimulated wells include: properly describing the hydraulic fractures, their geometry and position; and characterizing reservoir/ hydraulic-fracture properties. Innovative reservoir simulation techniques can optimize the number of hydraulic-fracturing stages required and realistically simulate their effect on production in heterogeneous reservoirs involving multiphase, multicomponent fluid-flow and adsorption/desorption mechanisms. However, the simulation approaches the E&P companies are utilizing, over simplify the complex growth and properties of hydraulic fractures, this might result in unreliable forecasts.This paper presents modern techniques to accurately simulate hydraulically-fractured wells. The developed methodology seamlessly integrates hydraulic-fracturing design/growth software to reservoir simulators to import detailed descriptions of hydraulic-fracture attributes; offers flexible gridding schemes and populates the mentioned properties to enhance the modeling and evaluation process. Main conclusions of achievements include generating more reliable forecasts that are critical in understanding wells performance and optimizing the productivity.This research has led to a game-changing methodology for the global E&P industry that enables operators develop an early understanding of stimulated wells performance where such detailed knowledge is vital to optimizing exploitation economics and estimation of unconventional reserves and resource potential.
Feasibility Study of Steam/Flue Gas Mixture Injection in Low Permeability Reservoir
Authors: Liu Renjing , Zhang Jianguo , Meng Liang , Liu Fei , Zuo Chao 
Published: February 2011

Abstract
Low permeability reservoir, with small pore radius, narrow throat and low permeability, accounts for a high proportion in the recent years. It is hard to develop by water flooding because of the high injection pressure. And thus gas injection is an attractive process owing to its high injection ability. However, gas channeling and poor flooding efficiency frequently occur during immiscible displacement, and thus the ultimate recovery is not as high as we expected.
To find a more effective method to resolve the problems above, we initially inject high temperature mixture gas of flue gas and steam to enhance oil recovery of low permeability reservoir, which combines the advantages of nitrogen gas injection, carbon dioxide injection and steam injection. In this paper, the experiments of different injection fluids, such as water, flue gas flooding, steam and high temperature mixture gas were conducted on low permeability natural cores under reservoir conditions. And the influence factors of mixture gas injection were investigated in detail by numerical simulation method.
The results show that, comparing with water flooding and flue gas flooding, the high temperature mixture gas flooding can enhance oil recovery dramatically. It can prevent gas breakthrough early and supplement formation energy quickly. It also can reduce heat loss and increase the heat areas. The steam distillation effect is enhanced during high temperature mixture gas injection, which can reduce residual oil saturation. The more proportion of carbon dioxide in mixture gas and the higher steam dryness are, the higher oil recovery enhanced is. There are different optimal injection rates and ratios of flue gas to steam under different reservoir conditions.
The result can be used to gas injection design and has great instruction meaning for the low permeability reservoir development.
Heavy Oil Characteristic Assessment for Field Facilities Selection Steam EOR: Case Study in Oman
Authors: Nengkoda Ardian , Hajri Moh'd , Armstrong Henry , Reerink Hendrikus , Chang Francis 
Published: February 2011

Abstract
Fluid characterization such assay composition, PVT and compatibility tendency are the most important issues in understanding the compositional behaviour identification and as an input for field facilities design and selection especially in steam EOR project for carbonate type of potential in Oman. The fluid characterization deals to addresses the following issues as such how many components should be used, how should the data be grouped and how should fluid description parameters be obtained and identified as early as possible to identify the major flow assurance issue across facilities. This paper discuss about integrated study and efective work flow to support the project Steam EOR facilities that cover 3 major facilities that are oil and gas processing, water treatment process and steam generation, each stages have been evaluated in correlation to identify a type of production chemical. As a result, the challenge of flow assurance issues are: heavy oil and water separation, H2S and CO2 generation from carbonate reservoir lead to corrosion and HSE, calcite scale, type of water treatment or desalination and steam quality management. The smart fluid characteristics assessment were mapped as a set of flowchart in identifying a critical physical or chemistry information, and determine the end fluid quality expectation, tolerance and economics. This paper demonstrate one example significance of fluid assessment for field development steam EOR project in Petroleum Development Oman, the concept are the real future vision for effective field facilities selection.
Trending of H2S from Reservoir After Acidizing from Well Contained SRB Bacteria: Souring Case Study in Southern Oman
Authors: Nengkoda Ardian , Mirza Muhammad , Ghozali Farid , Susandi Irman , Al Wardi Abdullah Ali 
Published: February 2011

Abstract
Ideally, a well stimulation activities is to increase production by improving such the flow of hydrocarbons from the drainage area into the well bore, however, however in one field in Southern of Oman, the acidizing created a trend of H2S increase. The common preliminary quick check usually will be based on the review of stimulation fluid characteristics whether carrying any sulphide or H2S and giving an impact to the wells. Some lesson learned in Oman is the water supply sources during the job always content H2S. The level of H2S after acidizing showed an alarming increase with time, casting doubts on future integrity assurance across the processing facility. As the materials used in the X and down stream receiving facilities are not to be NACE 175 souring compliant and consider H2S released are hazard for safety (HSE). The production chemistry and reservoir study have initiated an integrated H2S Monitoring and implemented a Mitigation Program by improving H2S onsite measurement and method revision and established proper well surveillance. As a result, the investigated the cause of souring show a positive SRB Bacteria and the acidizing cause a flash of H2S from Iron Sulfide scale as a product from bacteria populations. Overall its improved business performance, HSE awareness and saving the plant upgrade cost.
"SOYBEAN SLURRY" - A New Effective, Economical and Environmental Friendly Solution For Oil Congealing
Authors: Punase Abhishek D. , Bihani Abhishek D. , Patane Amol M. , John Ann , Arora Aman J. , Padalkar Chaitanya M. 
Published: February 2011

Abstract
The prospect of oil production from the Arctic region is attracting attention as the world is becoming more aware about the end of cheap and easy oil. The security and economic risks associated with the expensive and difficult oil remains very high. In deep-water projects, thousands of feet below the sea level, temperatures are near freezing. Combined with the high pressures present at these depths, oil congealment and ice-like hydrate formation is a commonly occurring phenomenon which results into flow restriction. This in turn leads to various production problems and hence substantial financial loss. To counter these problems, Soya slurry is proposed as an anti oil-congealer in this paper.
The soybean slurry consists of chemicals like Glycoprotein and unsaturated fats, which act as an anti freeze and suppresses ice nucleation effect. It is introduced in low concentration into the well bore which prevents the well bore fluid from congealing by increasing its thermal hysteresis and acting as an ice nucleation barrier. Even the viscosity of the wellbore fluid substantially reduces resulting in an easy and smooth flow through the pipeline with very less amount of friction experienced between the fluid and tubing.
Based on a detailed study, we have inferred that as soybeans are easy available, they have low cost and require simple application techniques, therefore they can provide an appropriate solution to the oil congealment problem.
This study will provide fresh physical insight into the phenomenon of anti oil congealer and help in countering the congealment problem in a more effective, economical and environment friendly way.
Tight Gas Reservoirs: Geological Evaluation of the Building Blocks
Authors: Shrivastava Chandramani , Lawatia Redha 
Published: February 2011

Abstract
Tight Gas Reservoirs (TGR) is attracting the attention of Oil & Gas industry from all quarters. Optimum exploitation depends upon the petrophysical evaluation and geological understanding. An insight into geological complexities of TGR is imperative to have a better evaluation of such reservoirs. This study details the tight gas sands (TGS) only as most of the TGR activities around the world are focused mainly on the clastics. It aims at explaining the different geological events that give rise to the tightness in the sandstone reservoirs and also presents a methodology to properly evaluate the geological complexities introduced. The TGS carry the imprint of both the primary depositional factors and secondary post-depositional ones. Grain size, sorting and distribution of detrital clay within a sequence stratigraphic framework govern the reservoir properties as depositional factors. Diagenesis is the key factor to control the tightness of the reservoirs after the deposition depending upon the compaction and cementation. Fractures are the post-depositional factors; the tectonic fractures along with the drilling induced ones provide an understanding of the stress regime and a clue towards planning the stimulation program. Conventional and sidewall cores with conventional open hole logs provide a larger understanding in terms of depositional environment and lithology variations. Detailed petrography with the help of XRD and SEM aids to understand the cementation pattern. Elemental capture spectroscopy and Spectral gamma logging can help correlating the cementation/ clay distribution within wells. Borehole images are quite helpful in capturing the textural variations which govern the differential diagenesis and also the drilling and natural fractures orientation and their association with rock facies. The study attempts to establish the need of proper geological evaluation which provides the building blocks for petrophysical and reservoir engineering evaluation to optimize the exploitation strategy.
Optimisation of Completions in Unconventional Reservoirs for Higher Ultimate Recovery
Authors: Snyder Daniel J. , Seale Rocky 
Published: February 2011

Abstract
Over the last decade, an industry wide shift to unconventional plays has occurred due to advances in technology allowing for the recovery of previously uneconomic reserves. The primary objective of completions in these unconventional reservoirs is to increase the effective surface area of the well to maximize reservoir contact. Horizontal drilling and multi-stage fracturing are two technologies which have accomplished this.
The two main methods of horizontal, multi-stage completions currently used in unconventional reservoirs are cemented liner "plug and perf" and open hole, multi-stage fracturing systems. This paper provides an introduction to unconventional reservoirs, describes the main methods of horizontal, multi-stage completions, and discusses how the choice of method can affect good fracturing practices as well as long-term production. Case study examples are presented from a variety of unconventional reservoirs including shale, tight sandstone and tight carbonate formations.
Operators working in a number of unconventional reservoirs, such as shales and other tight rock formations are experiencing faster than expected production decline rates, resulting in reduced long-term, ultimate recovery. This may be in part due to the abandonment of good fracturing practices with the advent of horizontal, multi-stage fracturing. Issues such as near wellbore conductivity, flowback, and fracture tortuosity, which can have a significant effect on the long-term production of wells, need to be considered when choosing a completion method, particularly for unconventional reservoirs.
Unconventional plays are becoming a significant part of the oil industry today and will become a bigger part in the future. It is important that the reservoirs are completed optimally to achieve maximum recovery. The information provided in this paper is applicable to unconventional resource plays worldwide.
A Study of Several Environmentally Friendly Clay Stabilizers
Authors: El-Monier I. A. , Nasr-El-Din H. A. 
Published: February 2011

Abstract
Quaternary amine-based chemicals have been used for many years as clay stabilizers. An Al/Zr-based clay stabilizer, A, was developed. It showed great effectiveness in mitigating fines migration and overcame the leaching effect of HCl. In this study, Stabilizer A was examined and its performance was compared with two commercial clay ones: tetramethyl ammonium chloride and choline chloride.
The type of cores (6 in. length and 1.5 in. diameter) that were used is Berea sandstone of 60-85 md; mainly contained 5 wt% kaolinite. Various coreflood experiments were performed to assess the effectiveness of each of the three stabilizers at 200 and 300°F. Inductively Coupled Plasma was used to analyze the core effluent to measure the concentrations of key cations.
During tetramethyl ammonium chloride and choline chloride corefloods, significant amount of fines were noted in the core effluent samples, which means that these stabilizers were not effective. A bad odor of ammonia was noted during mixing of choline chloride with HCl acid. Choline chloride was effective at high concentrations. Stabilizer A showed good behavior during coreflood experiments, and proved to be better than the two commercial stabilizers at low concentrations. Stabilizer A worked very well, and no bad smell or fines were produced. In addition, Stabilizer A is an inorganic-based fluid, environmentally friendly, and does not have any smell; in contrast to quaternary amine chemicals. Unlike previous Al-based stabilizers (hydroxy aluminum solutions), the new stabilizer was not removed by HCl and no decline in permeability was noted following HCl injection.
Life Extension and Assessment of Existing Offshore Structures
Authors: Solland Gunnar , Sigurdsson Gudfinnur , Ghosal Anupam 
Published: February 2011

Abstract
An increasing number of platforms are reaching their design life. For various reasons these platforms will require an assessment of their structural integrity. As examples one may experience operational changes of the platform that may lead to increased loads or there may be damages that reduce the structural capacity. Consequently, the design premises may have changed significantly and may result in increased uncertainty about the safety of the structure. In such cases the assessment process is focused towards reassuring that the structure has adequate safety.
When performing these assessments the engineer is faced with tasks where little guidance is found in design standards and the analyses that are required are often based on advanced techniques and methodology that seldom is used in design of new structures. The cost of doing advanced analysis is relatively low compared to replacement of an existing structure, but relatively high compared to moderate additions of e.g. steel in the design of a new structure. Design standards are based on theories, methods and experience for structures in a given design life (e.g. fatigue design and corrosion protection design). When this design life is extended, sound methods for ensuring that the structures are still sufficient safe is needed. Such methods will normally be "condition based design", where inspection, maintenance and repairs are included in the assessment in integrated way.
This paper discuss the overall assessment process for life extension and outline procedures connected to how to deal with the specific aspects that engineers meet when performing assessment for structural life extension.
On the basis property of the root functions of differential operators with matrix coefficients
Authors: Veliev Oktay 
Published: February 2011

Abstract
We obtain asymptotic formulas for eigenvalues and eigenfunctions of the operator generated by a system of ordinary differential equations with summable coefficients and periodic or antiperiodic boundary conditions. Then using these asymptotic formulas, we find necessary and sufficient conditions on the coefficients for which the system of eigenfunctions and associated functions of the operator under consideration forms a Riesz basis.
Does the Genitive Operate in the Hungarian Case System?: I. The é-Genitive
Authors: Bielecki Robert 
Published: February 2011

Does the Genitive Operate in the Hungarian Case System?: I. The é-Genitive
After three centuries of discussion concerning the genitive case in Hungarian, the authors of the latest academic grammars - in contrast to many of their predecessors - no longer distinguish this casal category. Different cases in Hungarian should, according to them, be distinguished only on the basis of their forms (endings). Such an extreme unilateral approach to this category seems to have simplified at first sight the description of the Hungarian language, erasing from it any case syncretism. From the point of the view defended in the present paper, however, talking about linguistic entities without taking into account their meaning is illusory; even in the case of meaningless speech segments such as phonemes it is the meaning of the segments in which they occur that constitutes the ultimate instance allowing them to be distinguished at all. The same applies to case. The moderate approach to the category of case adopted here, taking simultaneously into account its (i) morphological, (ii) semantic and (iii) syntactic properties, leads irrevocably to the restoration of the genitive in the description of the Hungarian language. As a specific feature of this language one should consider the sharp distinction between two subclasses of the genitive case: (i) the non-attributive (é-genitive) and (ii) the attributive genitive (Ø-/nak-/nek-genitive). Only the first of these (the é-genitive) will be discussed in detail. The second (the Ø-/nak-/nek-genitive) will be the subject of a continuation of the present paper. Recognition of the é-genitive seems to have been blocked by those of its properties which seem to be quite incongruous with those of other Hungarian cases. It is claimed, for example, that the marker -é - unlike the markers of other cases - seems not to express any syntagmatic function. This function is expressed by the case marker attached after the morpheme -é (A diákét (láttam) '(I saw) The student's one'). In the view of the author, however, the lack of syntagmatic function in the case of the morpheme -é is not so obvious. On the other hand, such "discrediting" properties for a case marker candidate, as the property of not occupying the final morphotactical position (diákét), can be viewed as entirely irrelevant for the category of case. The adopted approach seems to make possible a description of this fragment of the Hungarian case system from a more homogenous perspective, showing the interplay of different casal meanings within the boundaries of one word.