bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Inhibitor Squeeze Via Mechanistic Understanding of Inhibitor Chemistry
Authors: Tomson Mason B. , Kan Amy T. , Fu Gongmin 
Published: December 2007

Abstract
Chemical scale inhibitors are commonly used to prevent or inhibit scale formation in production. The most economic treatment of scale inhibitor is normally via chemical squeeze. However, there is little agreement regarding the primary mechanism by which the threshold scale inhibitors are retained in producing oil or gas formations as a result of squeeze procedures. Recent advances in phosphonate/rock interaction research at the Rice University Brine Chemistry Consortium have significantly improved our knowledge of what controls inhibitor placement in the formation. It is commonly suggested that reservoir type determines how an inhibitor is retained in a formation. Our research suggests that the pill chemistry is also an important determinant for retention of carbonate reservoir. Acidic pills are mostly retained near the well bore while more neutralized pills move farther into the formation. Three calcium nitrilomethylenephosphonate (NTMP) solid phases, an amorphous phase and two crystalline Ca2.5HNTMP phases with pKsp = 22.6 and pKsp = 24.2, are particularly important toward inhibitor retention. The relative sizes of these solid phases formed is governed by the pill composition and acidity. These results can be explained by a solution phase controlled sequence of reactions. All of this information has been incorperated into a new squeeze design software program, SqueezeSoftPitzer.
A New Class of Green Mineral Scale Inhibitors for Squeeze Treatments
Authors: Bazin B. , Kohler N. , Zaitoun A. , Johnson T. , Raaijmakers H. 
Published: December 2007

Abstract
The oil industry is currently facing severe restrictions concerning the discharge of oilfield chemicals into the environment. For most of the actual widely used mineral scale inhibitors, the future will depend on the possibility of their reinjection into disposal wells. Another alternative could be the deployment of biodegradable chemicals. For this purpose a new class of "green" scale inhibitors, the Carboxy Methyl Inulins (CMI), has been evaluated in its ability to prevent carbonate and sulfate scale deposition by squeeze treatments.
Jar Tests and Tube Blocking Tests, performed on actual reconstructed injection and production waters show that the CMI inhibitors exhibit competitive inhibiting performances compared to currently used scale inhibitors. Core tests for the determination of CMI adsorption / desorption properties in static and dynamic conditions help to predict inhibitor squeeze lifetime and to design its implementation in future squeeze applications.
It is finally concluded that the Carboxy Methyl Inulins may already be considered as viable alternate mineral scale inhibitors to currently used but not biodegradable chemicals.
Barium Sulphate Oilfield Scaling: Mathematical and Laboratory Modelling
Authors: Bedrikovetsky P. G. , Lopes R. P. , Gladstone P. M. , Rosário F. F. , Bezerra M. C. , Lima E. A. 
Published: December 2007

Abstract
The formation damage in scaled-up production wells caused by incompatibility of injected and formation waters have long been known. Precipitation of salts results in permeability decline. Among the most onerous of all scaling species is that of sulphates, particularly barium and strontium sulphates.
We study effects of porous media on the BaSO4 scaling kinetics.
A new methodology for determination of reaction rate coefficient from coreflood tests consists of the sequence of diffusivity reaction free tests, of transient tests with chemical reaction, and of simultaneous injections of both injected and formation waters with quasi steady state concentration profiles for barium and sulphate ions. The diffusivity tests serve for dispersivity coefficient determination. Quasi steady state tests allow determination of the reaction rate coefficient versus velocity. The transient test data as compared with the mathematical modelling data validate the model and the data of steady state test data treatment.
An analytical model developed is used for treatment of quasi steady state test data. The transient tests are treated by a numerical model.
The main result of the work is proportionality between the reaction rate coefficient and flow velocity for the parameter range studied.
Measurment and Prediction of Salt Formation in the Presence of Hydrate Organic Inhibitors
Authors: Masoudi R. , Tohidi B. , Danesh A. , Todd A. C. , Yang J. 
Published: December 2007

Abstract
Organic inhibitors (e.g. methanol, ethanol, ethylene glycol, triethylene glycol) are generally used to reduce the risk of gas hydrate formation in drilling and production operations. The addition of organic inhibitors has a significant adverse effect on the solubility of salts, increasing the risk of salt deposition. A better understanding of salting-out problems is necessary for effective design and implementation of flow assurance strategies in such complex systems.
In this communication we present an experimental investigation on the effect of methanol, ethanol and ethylene glycol on the solubility of several salts, including halite, sylvite and antarcticite. The results show that ethylene glycol has a much lesser adverse impact on salt deposition than methanol and ethanol. The details of an experimental set-up used for measuring salt solubility and salting out are described. The set-up could also provide valuable information on the effectiveness of various inhibitors used for preventing salt deposition in the presence or absence of gas hydrate organic inhibitors.
In addition, a novel predictive numerical approach is proposed to model salt formation in brine solutions with or without hydrate organic inhibitors. The model is based on the equality of the fugacity of salt in the solid phase and aqueous phase, which are calculated by an equation of state. The validity of the new developed model is demonstrated over a wide temperature range (i.e., −20 to 125 °C), salt concentration up to saturation point and hydrate inhibitor concentration up to 50 mass%.
First Lateral-Flow-Controlled Maximum Reservoir Contact (MRC) Well in Saudi Arabia: Drilling & Completion: Challenges & Achievements: Case Study
Authors: Nughaimish F. N. , Faraj O. A. , Al-Afaleg Nabeel , Al-Otaibi Uthman 
Published: December 2007

Abstract
This paper describes case histories of a successful drilling and completion experience of two tri-lateral Maximum Reservoir Contact (MRC) wells that were recently completed in Haradh field, Saudi Arabia. Equipping these two wells with down-hole monitoring and lateral flow-control, combined with the introduction of new completion practices, provided effective reservoir management solutions. A number of different MRC well designs were drilled and completed in different fields in Saudi Arabia, however, the subject two MRC wells were the first to provide minimum inter-lateral separation distance of three hundred meters. Moreover, these two MRC wells were the first to be completed with seven inch tubing string and tree, and equipped with per-lateral flow control option to selectively shut-in any water baring lateral in order to extend the life of such wells.
The objective behind the introduction of this new class of well design, the so called (MRC), which is generally defined as well with reservoir contact of five km and beyond, was to improve individual well productivity and hence reduce the unit development cost and to better develop hydrocarbon assets1.
Various reservoir and drilling challenges were encountered during the planning and execution phases of this project. Meeting the required minimum inter-lateral separation distance, expected production rate, and providing selective flow-control form each lateral were the main drivers for the current well design. Other challenges such as loss circulation, torque and drag limitations, well control, and formation damage were encountered while executing the project and were overcome successfully using different creative techniques that are also discussed in depth in this paper.
An Effective Fluid Formulation to Remove Drilling Fluid Mud Cake in Horizontal and Multi-lateral Wells
Authors: Nasr-El-Din H. A. , Al-Otaibi M. B. , Al-Qahtani A. A. , Samuel M. 
Published: December 2007

Abstract
Cleanup of drilling fluid filter-cake in long horizontal and multilateral wells is a difficult task. Both mechanical (water jetting) and chemical means (acids, oxidizers, and enzymes) have been used in the field. However, these methods have limitations, which can adversely affect well performance. Water jetting introduces large amounts of water into the formation, and can cause loss of well productivity through sanding and water blockage. Acids and oxidizers are very reactive and non-specific species. Enzymes can be used to degrade starch and xathan polymers. However, they are not effective in heterogeneous formations where there are high permeability streaks, which will require using large volumes of the treatment fluids, but with poor performance.
This paper examines using a combination of enzymes and a new class of viscoelastic surfactants. In this system, enzymes are used to degrade starch, whereas the visocelastic surfactant is used to increase the solution viscosity.
Extensive lab studies were conducted to examine compatibility of visocelastic surfactants with enzymes. The apparent viscosity of the enzyme/viscoleastic surfactant solutions was measured as a function of shear rate (57 to 1,740 s−1) and temperature (77 to 212°F). Surface tension was measured at various temperatures up to 284°F. Static (a HPHT fluid loss cell) tests were performed to assess the effectiveness of the combined system in cleaning filter cake formed by water-based drilling mud.
Experimental results indicated that the viscoelastic surfactant is compatible with the enzyme system. The low shear viscosity of the combined system is high enough to lift suspended solution during well flowback following the treatment. The addition of the viscoelastic surfactant to the enzyme solutions significantly reduced the surface tension of the enzyme solutions. This will reduce the time required to lift treatment fluids from the formation. The efficiency of the enzymes in degrading the polymers did not significantly change due to the presence of the surfactant.
Increased Assurance of Drill Cuttings Re-Injection - Challenges, Recent Advances and Case Studies
Authors: Guo Quanxin , Geehan Thomas , Ovalle Adriana 
Published: December 2007

Abstract
The handling of drill cuttings and wastes is both an environmental and economic issue in drilling operations. With ever-tightening environmental regulations and the green operation initiatives of operators, drill cuttings re-injection (CRI) into a subsurface geology often is the preferred option as it allows operators to achieve zero discharge since oily cuttings are returned to their place of origin.
When the technology started about a decade ago, injection into a single well had a maximum slurry volume of approximately 30,000 bbl. Now, particularly in very large projects, several million barrels of slurry may be injected into a single well. This represents more than a 1000 times the volume of a typical hydraulic fracturing job or more than 100 times that of those earlier cuttings re-injections. In some cases, the success of the CRI operation is critical because there either are no back-up options or the economic and environmental impacts are too significant.
This paper describes the challenges faced in CRI projects, along with recent advances and experiences gained in tackling these challenges through modeling, cuttings slurry and operational procedure design, monitoring and verification. For example, much progress has been made recently in slurry rheology design and operational procedure selection such as suspension/displacing to avoid loss of injectivity and to maximize disposal capacity and minimize HSE issues.
The authors also will present a risk-based approach, which integrates deterministic software and tools, available data, knowledge and experience, for modeling of geological and operational uncertainties and potential risks to increase the quality assurance. Case examples will be presented to illustrate the value of this integrated approach. Best practice guidelines and recommendations will be provided on data collection, design and engineering, operation and monitoring.
MWD Survey Accuracy Improvements Using Multistation Analysis
Authors: Chia C. R. , de Lima B. C. 
Published: December 2007

Abstract
Multistation analysis is a technique that provides drillstring magnetic interference compensation to magnetic surveys. This technique is now in common use in the industry, and this case study data verifies the capabilities of the multistation technique to improve measurement-while-drilling (MWD) azimuth measurement quality and accuracy. This study quantifies a significant improvement to standard MWD surveyed position uncertainty using actual survey data from drilling assemblies used in more than one hundred and twenty runs in over thirty-five different wells worldwide.
The use of multistation analysis, and the subsequent reduction in wellbore position uncertainty demonstrated can significantly reduce the overall surveying and drilling costs for the well, removing the need for correction runs and allowing for the penetration of smaller targets than previously possible with standard MWD surveying. This correction technique can be applied on a real-time basis at the point of surveying. Forecasting of the magnetization effects of the bottom hole assembly (BHA) using the same software, will also allow the driller to place the well more accurately. In some cases the use of multistation analysis with standard MWD surveys will enable the removal of one or more gyrocompass surveys from the survey program. This can reduce overall surveying time and cost, and the exposure of the BHA to additional stuck-in-hole risks that occur when running wireline surveying tools through drillpipe in extended-reach wells.
The main analysis method is based on a direct comparison of MWD survey data before and after multistation correction, against independent overlapping gyro survey data. The results achieved by this study are translated directly into improvements in current industry standard error models, and this paper proposes a standard error model for multistation analysis corrected MWD survey data.
A Case Based Knowledge Repository for Drilling Optimization
Authors: Perry P. B. , Curry D. A. , Kerridge J. D. , Lawton J. , Bowden D. , Flett A. N. 
Published: December 2007

Abstract
Drilling knowledge management applications are often criticized as lacking in structure and providing little value return to users due to lack of relevant content and difficulty of use. The drilling optimization group of a major service company identified knowledge management as one of the enabling technologies for service delivery and embarked on an initiative to create a knowledge management system that addressed these key weaknesses.
Previous collaboration with a major operator led to the development of a generic best practice system for drilling performance optimization. We have now supplemented that system with a separate but linked knowledge tool that allows us to capture and share the specific technical lessons learned by our engineers in their project work. This new tool promotes sharing of new knowledge amongst our optimization engineers. It gives company-wide access to the new knowledge they create. And the new knowledge it captures is used to update the generic best practice system.
Proven knowledge engineering techniques were used to create an ontology of the drilling optimization domain, which was in turn used as the basis for the new knowledge tool’s structure. The knowledge tool is used to capture all projects undertaken by the group and the main technical and process lessons learned in those projects. It is therefore a repository for case-based drilling performance knowledge. Entries created by applications engineers are processed and reviewed by technical experts prior to publication to the global community. The knowledge is structured according to problem, operating practice and the applicable phase of the project. A key element is the physical description of the downhole environment in which each lesson was learned. A structured search facility allows engineers to locate lessons learned and performance achieved in drilling environments that are physically equivalent but geographically distinct to those of the well they are studying.
This paper shows how knowledge engineering and knowledge management techniques have been adopted to structure drilling knowledge, increasing its quality and ability to be re-used. We show how the new knowledge tool aids rapid location of relevant knowledge and further how the use of structured knowledge facilitates integration of different knowledge tools and updating of best practices. Several case histories are presented that show how use of the system has delivered real drilling performance improvements by communicating learning across geographic boundaries.
Improving the Success Rate of Collaborative Drilling Projects
Authors: Morrice William , Vann Martin 
Published: December 2007

Abstract
There is a growing trend toward collaborative relationships between traditional operating companies and major service companies, either for specific projects, or in the guise of longer-term technical partnerships. Often these relationships are characterized as a vehicle for transferring technology and sharing best practices. Clearly defining expectations and success criteria for all parties is essential, but not always straightforward. Issues related to job security, competence, and internal competition often arise, which can cause such projects to fail if not recognized and managed. This paper describes a process to establish and maintain collaborative relationships, improving the prospects of success.
Extending the Boundries of Casing Drilling
Authors: Fisher Antony , Reid Doug , Tan Ming Zo , Galloway Greg 
Published: December 2007

Abstract

Proposal
Shell has targeted casing and liner drilling as one of five mature technologies for an accelerated uptake within its group E & P companies. A 9 5/8" surface casing drilling job performed onshore Brunei in September 2003 utilized a new design of casing drill shoe that extends the depth range of rotary casing drilling. The convertible drill shoe has a novel feature that allows the cutting structure and blades to be extruded outwards once section TD is reached. By this process, the drill shoe converts to a cementing shoe, allowing the casing to be cemented in place. The cementing shoe and next hole section can then be drilled without interference from the casing drill shoe cutting structure and blades. Application of the extrusion process allows a more aggressive and durable cutting structure on the casing drill shoe and hence allows deeper, more resistant formations to be drilled.
The paper will describe the planning, implementation and subsequent results from this world’s first convertible casing drill shoe job that led to a world record depth achieved for this type of rotary casing drilling, and a cost effective option for setting vertical surface casings.
Integrated Team Approach to Zonal Isolation Creates Value
Authors: Luckanakul Nat , Davidson John P. , Weber Lawrence , Hibbeler Jeff 
Published: December 2007

Abstract
Best Practices for cementing are well established in the industry however there remains the continuous challenge of effectively employing these best practices in balancing the need for drilling performance and the need for delivering the best possible well to production. For multi-zone monobore completions where the cemented tubing annulus is the single means for zonal isolation, this becomes a critical goal. Such is the case with the majority of wells drilled in the Gulf of Thailand. Desire to meet this challenge led to the creation of a full-circle process that both provides the methodology and initiates the inter-disciplinary communication necessary to improve zonal isolation and the added value it will bring. Components of the full-circle process employed in Thailand include: creating a cementing "scorecard" to focus operations on cementing best practices; forming a cross-disciplinary team of drilling, completion; production and contractor personnel to review bond logs, adjusting drilling practices; and communicating to all involved in the process.
An integrated team approach developed within the context of the full-circle process has successfully linked the goals of the Subsurface Operations and Production Departments resulting in the creation of more production opportunity and maximized recovery rates. The CBL Review Team (CBLRT) created in late 2002 consists of drilling, completions and reservoir engineers, along with logging and cementing experts from the representative service providers. In many cases members of the Asset Management team also attend the regular weekly meetings. To date, the team has reviewed over 450 wells.
This paper presents the full-circle process model and shows how improving zone isolation, evaluation methods and field results can be adapted for application in other operating environments.
Well Intervention Management in Oman Fields
Authors: Aihevba Leste O. 
Published: December 2007

Abstract

Summary
The Northern Oil Directorate of PDO (OND) manages some of the most important assets in the country, contributing just a little under 50% of Oman's daily production. Over the last 5 years, the production has seen a rapid decline. The challenge of arresting this decline to maximize the reserves is being met by a significant increase in the level of well intervention following re-emphasis on four major areas: Proper well surveillance, Acceleration of reserves by Optimization activities, Maintenance of NFA by restoration activities and Conservation of reservoir energy by management of water-floods. Major well services challenges are in the areas of well and reservoir surveillance, failed ESP replacements, well integrity (casing, tubing and packer) repairs, additional perforations, water shut off, gas lift optimization and multi lateral re-entry. Well Services expenditure has more than doubled in 4 years, with over 5000 entries, (utilizing hoists, coiled tubing, Wireline, pumping units) expected in 2004. Management of this rapidly increasing level of activity was imperative to realize value for the asset from the increased expenditure.
This paper discusses the process applied to management of Well Services activities with a refocus on lowering intervention costs, increasing net oil rewards and reducing deferment, building on the principle that every action costs money, and should therefore result in some oil in the tank. It takes us through the approach of integrated analysis of information from an increased level of surveillance activities to generating a more robust portfolio of intervention candidates. It highlights the improvements made on candidate selection, ranking, activity proposal generation, resource allocation, activity execution, performance management, KPI tracking and after action reviews. It concludes with a description of the feedback loop being embedded to ensure continuous improvement, the benefits realized so far and what more needs to be done.