bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Safety Awareness—A Field Study
Authors: Gilmore T. , Gritto S. , Steinback S. , Clayton M. 
Published: December 2007

Abstract
Safety performance, safety awareness, and safety reporting are becoming more and more prevalent in the industry today, with progressively more operators paying greater attention to contractor Quality Health Safety and Environment (QHSE) Management. Contractor effectiveness in QHSE management is being used as means to eliminate a contractor who does not meet minimum established standards. Consequently, more resources now being placed upon preventative measures which reduce accidents and incidents, some of which are described in this paper.
Many QHSE Management programs fail due to a "Top Down" only approach. If the entire workforce, from bottom to top, is not convinced, an organization will just be going through the motions. They will not realize any real benefit and more importantly, will not be instilling the safety habits that make an HSE program successful. As managers supervisors and engineers, we recognize the importance and value added to an operation by implementing safety systems and by setting safety targets that continuously challenge us to improve safety. The question then becomes how to build safety compliance by engraining a safety culture into everyday activities and into each individual employee, using cost effective resources and with a synergy that compliments, not compromises, service delivery to the customer.
This paper outlines how to move from a "Top Down" safety management approach to one balanced by both employee and management feed back. The balanced approach to safety, through an example of the efforts made in one Oilfield Service Company operating location will be demonstrated. It explains how the message is passed on to and ingrained into the workforce to solicit their understanding, participation and "Buy-In". Once the workforce buys in, it is demonstrated that QHSE becomes second nature to all personnel. As everyone becomes involved, the number of days without a Lost Time Accident (LTA) starts to become a part of his or her daily life, rather than an abstract figure reported monthly by the manager. The importance of visible closure of action plans with continual feedback, has been shown to play a very important role in convincing the workforce that the system is real and that the company is serious about QHSE. This, together with a consistent zero tolerance policy and a no blame culture, will reinforce the most important factor - commitment.
This paper will also demonstrate that with the use of available management tools such as communication, management visibility, standard practices, employee empowerment, leadership by example, training, delegation, quality control, recognition & reward, and the setting of challenging and achievable objectives, a sustainable, successful QHSE program can be developed.
Utilizing an Automated Annular Pressure Control System for Managed Pressure Drilling in Mature Offshore Oilfields
Authors: Reitsma D. , van Riet E. 
Published: December 2007

Abstract
Shell International Exploration and Production B.V. Research & Development has developed an automated choke manifold capable of maintaining a relatively constant bottomhole pressure while drilling. The Dynamic Annular Pressure Control System prototype was successfully tested in 2003, followed by a long-term trial on a deep geothermal well in 2004, proving the robust nature of the design. Two new systems have now been prepared for offshore use. One choke system has been deployed for use in the UK sector of the North Sea and a hybrid system deployed in the Gulf of Mexico. Both applications require the bottomhole pressure to be maintained at a relatively constant value in order to maintain borehole stability. Both applications are in mature offshore oilfields where narrow pressure margins would result in borehole collapse if conventional drilling methods were employed. The development of the choke manifold systems, application and results will be discussed.
Packerless Multistage Fracture-Stimulation Method Using CT Perforating and Annular Path Pumping
Authors: East L. , Rosato J. , Farabee M. , McDaniel B. W. 
Published: December 2007

AbstractRecord high prices for oil and gas have increased the opportunity for producers to maximize the value of their assets. Under current market conditions, reservoirs previously considered marginal or even noneconomic can yield an acceptable return on investment and are increasingly considered for well completion. Many are lower-permeability formations that require fracture stimulation during the completion phase to deliver economic rates. In the latter part of 2004, a new stimulation technique was introduced to the industry, providing well operators a method to achieve multiple-zone fracture stimulation while controlling stimulation costs. By mid-2005, this new process had been evaluated by several operators in the US as well as Canada and Australia with very positive results.This new process offers the opportunity to perforate and stimulate multiple pay zones with a single well intervention, often within a single day. The technique employs a hydraulic jetting assembly on coiled tubing (CT) to erode perforations, immediately followed by pumping a fracture-stimulation treatment through the annulus between CT and casing. At the completion of the first fracturing stage, small-volume, high-proppant-concentration slurry is left in the wellbore to provide isolation of the just-stimulated zone from subsequent targets. In some applications, a wellbore screenout may also be induced to improve the temporary isolation of this zone. This sequence (perforate, stimulate, isolate) is repeated until all desired zones have been treated. Following the final stimulation stage, the well is cleaned out with CT and turned over to production. If needed, N2 gas can be pumped through the CT to kick-off the return flow.This paper describes the operational aspects, advantages, and limitations of using this new multistage perforating and fracturing technique with example field applications.
New PDC Technology Significantly Improves Performance in Drilling Deep Khuff Wells for a Major Operator in Abu Dhabi
Authors: Jaffar A. , Birch R. , Teasdale P. , Ani S. A. 
Published: December 2007

Abstract
Drilling the 12¼" and 8½" sections in offshore Abu Dhabi's Deep Khuff fields is very challenging due to an intricate geological sequence that consists of limestone, dolomite and shales that are highly interbedded with hard stringers. Historically, ADMA-OPCO, the operator, has attempted to efficiently drill the section using roller cone tungsten carbide inserts (TCI), natural diamond and polycrystalline diamond compact (PDC) technology.
PDC bits yielded better performance in terms of rate of penetration (ROP) and bit life over TCI bits. However, it required several PDC bits to drill the sections. Further detailed analysis produced optimum PDC designs that successfully established new benchmarks in the fields.
The objective was to minimize the number of bit trips by enhancing PDC bits performance. This called for new PDC technology coupled with optimized motor drive. To address this challenge, ADMA-OPCO and bit vendor and other service companies worked together to seek optimized solutions to drill the interbedded rocks efficiently.
This paper reviews the findings of the detailed study in drilling the 12¼" and 8½" sections in typical Deep Khuff wells. The study showed that PDC damage from encountering harder stringers was the primary impediment to achieving better performance. Subsequent to the recommendations, the challenges were overcome by utilizing new PDC cutting structure designs and advanced cutter technology along with optimized downhole motor assemblies. The resultant improvement is also demonstrated by examples from separate fields offshore Abu Dhabi where considerable savings were achieved in terms of footage drilled and cost per foot.
Deployment of High-Horsepower ESPs To Extend Brent Field Life
Authors: Blanksby J. , Hicking S. , Milne W. 
Published: December 2007

Abstract
The Brent field in the Northern North Sea is enjoying an extended life partly due to installation of electrical submersible pumps (ESPs) to back-produce water from the reservoir. ESPs have been deployed with some success to prolong reservoir depressurisation in order to replenish the gas cap for subsequent production.
This is the first offshore application of ESPs for this purpose and differs from water production from aquifer wells for reinjection purposes. Moreover it has not been achieved without overcoming technical challenges such as minimal control during start-up, the use of fixed-speed drives, operating high horsepower motors, and a large degree of sub- surface uncertainty.
The equipment selected for the ESP system is described, including downhole and topsides equipment. An extensive development and testing programme was undertaken to qualify the pump and motor design for this unusual duty.
Lessons learned from the testing, commissioning and operational phase of the project are discussed.
Improved Wavelet Filtering and Compression of Production Data
Authors: Olsen S. , Nordtvedt J. -E. 
Published: December 2007

Abstract
This paper investigates filtering and compression of real-time production data by means of wavelets. We conduct a comprehensive analysis examining a series of possible wavelets for this type of data, and demonstrate that spline39 and spline4246 have excellent properties for cleansing of pressure and rate data, respectively. We extend the wavelet filtering technique for E&P data in several ways. We demonstrate that the methods frequently used for noise estimation give erroneously results, and that the noise estimation will depend on the wavelet utilized. New noise estimators are developed. We show that the new noise estimators combined with a median filter are suited for removal of outliers. We demonstrate that the SCAD shrinkage rule gives best results together with spline39 for pressure and spline4246 for rate. We show the choosing a higher filter level than those common used will be beneficial. A new empirical threshold estimator is proposed, giving excellent results compared to the other commonly used threshold estimators. A new compression routine for automatically compression of signals is proposed, finding the optimal compression ratio for piecewise constant signals like rate data. The filter approach proposed in this paper requires no user interaction, and can thus be performed automatically. In most cases, noise reduction at 85% or above is achieved.
Laboratory Studies of In-Situ Generated Acid To Remove Filter Cake in Gas Wells
Authors: Nasr-El-Din H. A. , Al-Otaibi M. B. , Al-Qahtani A. A. , McKay I. D. 
Published: December 2007

Abstract
Many horizontal/multilateral wells are drilled using water-based mud. In general, drilling fluids consist of xanthan, starch or polyanionic cellulose with bridging agents like sized calcium carbonate and salt particulates. During drilling and completion operations, it is essential to form an external filter cake to control fluid losses. However, effective filter cake removal during well completion is very difficult to achieve, especially in low permeability formations. Increasing use of long horizontal and multi-lateral wells with very low draw-down makes efficient cleaning and stimulation treatments even more challenging. Placement of corrosive acids to dissolve carbonate is problematic particularly in horizontal wells with extended reach. Polymer-breaking enzymes and oxidizers are effective at degrading polymer residues present in the wellbore, but will not attack carbonate or other acid-soluble materials.
A new fluid addresses several key problems inherent in removal of drilling fluid filter cake, cleaning, and stimulation treatments of horizontal and multilateral wells. This fluid generates an organic acid (acetic or formic) in-situ, thus providing a very controlled acidising process for mud solids. The fluid can also incorporate enzymes to remove biopolymers. Several lab experiments were conducted to examine the compatibility of fluids with enzymes. The kinetics of acid producing reactions were examined in detail. A modified HPHT fluid loss cell was used to assess the effectiveness of the system in cleaning drill-in fluid damage. The surface tension of fresh and spent acid was measured as a function of temperature.
Lab results indicated that the fluid is compatible with the enzyme system. Also, the fluid is non-corrosive and has minimum impact on well tubulars. Unlike conventional reactive acids such as HCl, the slow reaction kinetics ensure better distribution of the new fluid across long sections with minimal leak-off during pumping. The HPHT tests showed a significant improvement in the efficiency of removing filter cake. Surface tension measurements indicated that the spent acid solution had low surface tension, which will accelerate lifting these fluids from tight formations.
Discharge of Produced Water in the North Sea: Where We Are, Where We Go.
Authors: Garland E. 
Published: December 2007

Abstract
Since the Paris Commission has taken its first measures regarding the discharge of produced water from offshore installations into the North Sea at the end of the 1970s, the provisional performance standard set at that time has remained unchanged. In fact that provisional performance standard (limiting the content of oil at 40 mg per litre of water discharged) was a challenge, and industry spent billions of $US to treat the billions of cubic meters of produced water which have been discharged since then. It led to the development of new treatment techniques, the prominent one being the hydrocyclones in the 1990s.
Measures taken by OSPAR in 2000 regarding chemicals used and discharged offshore and in 2001 regarding the management of produced water dramatically changed the picture, giving an impetus to development of new techniques - some of which being now fully implemented-,to reconsider water management, shut-off techniques, and last but not least, re-injection, a technique which, for many reasons, has been less used in the North Sea than in other regions of the world.
The global average oil content of the water discharged in the North Sea is significantly lower than the upper limit set by the regulators. Nevertheless, not only some installations still face serious difficulties to meet this old performance standard, but the measures taken by OSPAR at the beginning of the 2000s actually go far beyond that standard, create constraints on compounds in produced water other than aliphatic hydrocarbons, and development of new technologies as well as a review of the approach of the operators of produced water treatment and disposal routes need to be dramatically reconsider.
Optimization of Borehole Stability Using 3D Stress Optimization
Authors: Kårstad E. , Aadnoy B. S. 
Published: December 2007

Abstract
Borehole stability has played an important role in the evolution of long and deep wells in later years. Borehole collapse and circulation losses are costly problems for the entire drilling industry.
It is often assumed that high borehole inclination leads to lower mud weight margins. To investigate this aspect, a study of borehole stability in 3-dimensional space was undertaken. This paper presents results and applications of the findings in this study.
The in-situ stress state plays a key role for borehole instability. The stress state is usually classified as normal fault, strike/slip fault and reverse fault stress states. One major conclusion of the study was that optimum stability was obtained for a lithostatic stress state, which is where all 3 normal borehole stresses are equal. For this case the window between fracturing and collapse was maximum. Bounds on the magnitude of the in-situ stresses were also invoked, resulting in a constrained 3-dimensional model that covered both fracturing and collapse pressures.
Studying both fracturing and collapse pressures, it was found that maximum hole stability could be obtained at intermediate orientations, and that they are controlled be the magnitude and directions of the in-situ stresses.
Field cases are also presented in the paper. It is shown that under optimal conditions combination of wellbore inclinations and azimuths can give the highest wellbore stability.
The 3-dimensional fracture and collapse model presented is an efficient tool for well path optimization. Platform placement and planning of difficult wells can be improved by using this method. It is presented as analytical equations, and can easily be implemented in a calculator.
Calculation of Drillpipe Rotation Effects on Fluids in Axial Flow: An Engineering Approach
Authors: Hemphill T. , Ravi K. 
Published: December 2007

Abstract
The usefulness of drill pipe rotation in drilling and cementation has been debated over the past several years. In recent years, the positive effects of pipe rotation on hole cleaning, particularly in highly-deviated wellbores, has been noted. However, many engineers are unsure of the usefulness of drill pipe rotation because the effect has not been quantified. One reason for this is that the effect of drill pipe rotation on non-Newtonian drilling fluids in annular flow is not a well understood phenomenon. There has been no single, valid method developed to mathematically characterize rotation effects on point velocities for non-Newtonian fluids in axial flow.
In this paper, the effect of drill string rotation on axial flow is investigated from a fluid dynamics perspective. Using the Herschel-Bulkley rheological model, calculations for pure laminar flow and rotation are coupled to obtain shear rate characterization across the annulus. Developed first for fluids in concentric flow, these methods will be later expanded to handle the effects of drill pipe rotation in eccentric geometries.
Using this method to mathematically characterize the effect of drill string rotation on axial velocity can lead to better understanding of annular flow behavior under normal drilling and circulating conditions. Areas such as hole cleaning in high angle wellbores, rotation speeds necessary to effect good annular cleanup prior to cementing, etc., will find useful application for this mathematical modeling technique. Moreover, in today's complex wells where a narrow operating window exists between pore pressure and fracture gradients, any improved understanding of factors that change annular pressure drop and velocity patterns can be critical to the success of the drilling operation.
Optimized Test Sequences for Formation Tester Operations
Authors: Pop J. , Follini J. -M. , Chang Y. 
Published: December 2007

Abstract
The setting of pretest parameters for the acquisition of pressure and mobility data with wireline formation testers has largely been left to field engineers operating the tool and their knowledge of local conditions. If the test sequence is not successful the pretest parameters, such as the number of drawdowns, pretest volume, rate and duration, are either adjusted to achieve a better result or the tool is moved to a nearby location where the chance of success is deemed to be better. This strategy "works" if the information necessary to make an assessment is readily available. During drilling operations, where telemetry rates are usually very low and test times are necessarily short, this approach is not likely to be acceptable.
This paper describes pretest sequences that optimize the process of acquiring pressure and mobility data during formation tester operations without compromising the quality of the data. All sequences employed consist of three phases: identification when the mud cake has been breached and the sandface pressure is below formation pressure; a short "investigation" phase in which the formation is interrogated to obtain an initial estimate of its properties; and one or more "measurement" phases in which the best estimates of the formation pressure and mobility are obtained. The measurement phases use the information acquired during the investigation and/or previous measurement phases to design an optimal test sequence such that a stabilized sandface pressure is achieved at the end of each measurement phase subject to an overall time constraint. This is done in the downhole tool by solving a small- scale optimization problem. Associated with the sequences are quality indices derived from the results of the individual phases that indicate how well the procedure has succeeded and the validity of the data acquired.
The test sequences have been implemented on standard wireline formation tester tools and a formation pressure while drilling tool. Field trials with the new sequences are discussed and the results are compared with standard operating sequences.
Alaska Kuparuk North Slope Oil Separator Upgrade: Case Study
Authors: Lees R. 
Published: December 2007

Abstract
Located on the Arctic Coastal Plain, 40 miles west of Prudhoe Bay, ConocoPhillips Kuparuk facility on Alaska's North Slope is the second largest oilfield in North America. At CPF1, ConocoPhillips brought on a new field with heavy oil and high solids content which necessitated upgrading the 1st Stage production separator. The original separator level instrumentation, used for the past 23 years, utilised traditional displacers and differential pressure cells for both oil and interface measurements.
In an environment where extreme winter temperatures of minus 60 deg F (-120 deg F with wind chill) are the norm then high reliability and maintenance free operation comes very high in the specification of instruments. This case study shows, with operator feedback and ‘real time’ ‘on line’ screen shots and trending data, how various novel and traditional level measurement technologies performed under these conditions of extreme temperature and dealing with difficult to separate oil with a high solids concentration. The technologies under review included the Tracerco Profiler, Guided Wave Radar, internal displacers and external differential pressure cells.
"The new technology Tracerco profiler has been extremely helpful in identifying emulsion build-up, allowing us to attack it quickly with chemicals. We have also been able to improve the interface control tuning on the water outlet valves. We have not seen much foaming, but that may be because we are treating with a lot of antifoam. The sand monitoring capability was an unexpected benefit. Operations knew all along it could see sand, but we didn't expect to use it like we have been. We anticipated sandjetting the vessel about once per week as we have for the past 23 years, but with the new heavy oil field producing an order of magnitude more than that, knowing when to sand jet (almost daily now) has been a huge advantage."
Managing Safety—Focusing on High Potential Risks and Incidents
Authors: Sixma E. , Rutten K. 
Published: December 2007

Abstract
Over the last few decades, the Shell Group has been quite successful in reducing LTIF and TRCF by focusing on these indicators, but this has not resulted in an equally significant reduction in FAR.
One explanation for this is seen to lie in the fact that the incident "iceberg" has a significantly different shape for different classes of activities.
Focusing on reducing LTIF and TRCF can result in a focusing on the wrong class of activities, which actually contribute less to the overall FAR.