bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hse Management System Challenge
Authors: Ibrahim Reda 
Published: December 2007

Abstract
It is generally accepted that the effective management of HSE is an essential aspect of drilling industry. This is particularly so during a period of manpower and cost reduction when it is important to ensure that budget constraints do not lead to lower standards of, for example, manpower training or equipment maintenance. Indeed, it is in these very circumstances that it must be recognized that properly directed expenditure on HSE can lead to an overall reduction in costs.
The management process is often described in terms of a simple control system. The manager must establish the overall objectives, develop and implement plans to achieve the objectives, and then monitor progress and exercise control until the ultimate goal is achieved.
The real challenge facing management is to organize, equip and motivate the two different operations group (offshore and onshore) of personnel to have something done. This applies equally to HSE although the ultimate aim is quite different since it is to ensure that certain things never happen. Having this accepted by managers and supervisors who are accustomed to being judged on their achievements is a particular difficulty we have to face.
Formation Drillability-Definition, Quantification and Contributions to Bit Performance Evaluation
Authors: Mensa-Wilmot Graham , Calhoun Bill , Perrin Van P. 
Published: December 2007

Abstract
Current improvements in bit performance, though normally attributed to advancements in product development1,2, have greatly benefited from the science of formation characterization. Determination of rock mechanical properties, such as bulk compressibility, Poisson's ratio, internal friction angle, shear and compressive strengths from well log data continues to improve the bit selection and application processes. In fact, product development would not be at its present pace, without the influences of formation evaluation.
Several analytical methods3,4 have been developed by the industry for formation characterization purposes. Although these tools are effective, most of them fall short when there is a need to predict the performance of a given bit in a known field. In addition, they present a micro-scale evaluation of the formations to be drilled, making it difficult to establish and compare drillabilities in a given field or between different fields. Additional disadvantages of the current evaluation methods are that they presumptuously draw parallels between formation hardness and drilling difficulty, without establishing the relationships required to make the needed comparisons.
This paper will present a new bit performance evaluation parameter – formation Drillability (FD). It will establish a process for the determination of FD, which combines the different rock mechanical properties into a single dimensionless parameter. This approach addresses the limitations of the current evaluation processes by establishing an effective method for bit performance evaluation and prediction. FD establishes a macro-level evaluation process, which enables drillabilities to be quantified for different fields. Most importantly, FD improves operational efficiency by enhancing the development, selection and application of all types of drill bits.
Improving Drilling Efficiency Through the Application of PERFORM Performance by Risk Management
Authors: Anadrill W. D. Aldred 
Published: December 2007

Abstract
A new initiative to enhance drilling performance has been introduced to the industry. The initiative is based on close cooperation between the Operator and the Service Company as well as the integration of planning and real time drilling solutions to significantly reduce operational cost and non-productive time.
The paper shows how a risk management and loss control framework can be used to combine the technical expertise and drilling measurements provided by Schlumberger, with the knowledge and experience of the operators to develop solutions for enhanced drilling performance. Teamwork and establishment of good communication systems are essential factors in getting the solutions implemented.
Some of the key drilling areas where the strategy and tools have been applied are:
Stuck Pipe and Lost in Hole (LIH) Avoidance Drillstring Failure Prevention Wellbore Stability and Losses Drilling Efficiency, ROP and Bit Optimization Pore Pressure analysis and Influx prevention
This paper describes the experience of the PERFORM strategy applied in several locations around the world. Examples will be presented from projects that have been completed in a range of geographic and drilling conditions, where clients have reported reductions of NPT from an average of 40% to 4%, finishing hole section 10-14 days ahead of schedule.
Validation of Carbonate Matrix Stimulation Models
Authors: Fredd C. N. , Miller M. J. 
Published: December 2007

Abstract
The successful matrix stimulation of carbonate reservoirs requires that live acid penetrate past the formation damage. Effective acid penetration is facilitated either by transport through natural fractures or the formation of dissolution channels (wormholes) during the acidizing process. The optimal formation of wormholes and/or transport of live acid along natural fractures depends on the rate of reaction between the acid and the formation minerals, the rate of acid transport to the mineral surface, and the rate of acid convection along the wormhole and/or fracture. There are three prevailing theories in the literature that estimate the efficacy of acid stimulation treatments in carbonate formations. These theories predict the conditions at which wormhole formation occurs most efficiently and are based on the existence of: 1) an optimum injection rate at a transition between reaction-rate limited and fluid-loss limited regimes, 2) an optimum Peclet number, and 3) an optimum Damköhler number.
The models are compared with a large set of experimental data representing a wide range of conditions encountered worldwide. The results show the conditions under which each theory is most appropriate. Parameters studied include injection rate, temperature, and fluid-mineral system. Validated models are then used to simulate skin evolution during actual matrix acidizing treatments. Results of the laboratory and field validations highlight gaps in the current technology and provide directions for further investigation.
Development and Deployment of a Scale Squeeze Enhancer and Oil-Soluble Scale Inhibitor To Avoid Deferred Oil Production Losses During Squeezing Low-Water Cut Wells, North Slope, Alaska
Authors: Jordan M. M. , Graff C. J. , Cooper K. N. 
Published: December 2007

Abstract
The paper outlines the experimental work that has been carried out to develop an effective treatment strategy for production wells, specifically those with electrical submersible pumps (ESP’s) that suffered significant performance impairment at water cuts of less than 5% due to carbonate scale deposited within the ESP’s. These Alaskan production wells had been treated for a couple of years using aqueous based scale inhibitor squeezes. Many of these treatments resulted in a significant 10% to 20% reduction in the oil production rate following the squeeze. The damage mechanism was investigated by coreflooding and revealed to be a combination of water block and relative permeability effects. Following the damage investigation coreflood, a second study was undertaken to investigate a chemical treatment to remove the damage already present within the near well bore and prevent further deposition of scale. The result of this test program was the development of a treatment strategy which used a solvent package followed by an oil soluble scale inhibitor. Field results of this type of treatment suggest that the wells treated with this chemical system did not suffer any reduction in oil production rate and were effectively protected from carbonate scale. Wells that had been damaged by the previous aqueous treatments could be stimulated and the lost oil production recovered. Reference is also made to the development of an improved aqueous based squeeze treatments for the treatment of higher water cut wells.
Designing and Completing High-Rate Oil Producers in a Deepwater Unconsolidated Sand
Authors: Porter D. A. , Johnston R. A. , Mullen M. E. 
Published: December 2007

Abstract
The Troika Subsea development project has produced the top four hydrocarbon producing wells in the Gulf of Mexico – three wells each delivering greater than 40,000 STBOE/D sustained rate. This paper will give the reader an overview of the completion designs and installations, but equally important, what lessons we learned to apply on our next deepwater high rate producers.
The Troika field is located in 2700’ of water and was a fast paced development project which was delivered (from discovery to first oil production) in only 39 months – a deepwater industry record! This subsea development consists of five subsea wells clustered around a production manifold and tied-back 14 miles to the host platform. Many well design aspects, various technologies, and timing issues had to converge quickly for the success of this project.
Completion practices will be reviewed and resulting productivity performances will be charted. The following areas will be discussed: Well performance historyPerforating practicesFluid loss control practicesSand control operationsTubing installationFlowback operationsSubsea operationsBatch operationsPersonnel and training
Optimizing Perforating Strategy in Well Completions to Maximize Productivity
Authors: Underdown D. R. , Jenkins W. H. , Pitts A. , Venkitaraman A. , Li H. 
Published: December 2007

Abstract
The Britannia field is a gas producing reservoir operated jointly by Chevron and Conoco. Prior to completion of the wells, two major concerns were raised: potential sand production (perforation stability), and the optimum underbalance (for zero perforation skin) during completion. Theoretical models were used to predict the optimum underbalance based on log derived formation properties. Using detailed log permeability data numerous simulations were carried out to choose the gun, charges, shot density and perforating strategy for optimum productivity. Different shot densities and charges were used in different sections of the formation based on simulation results as opposed to choosing perforation parameters based on average well properties.
Experiments were conducted to confirm the theoretical underbalance predictions and to investigate the stability of perforation tunnels at high underbalance pressures. Reservoir and outcrop core samples were perforated at simulated downhole conditions in the laboratory at different underbalances based on values obtained from the model. Flow performance evaluation of the perforated reservoir core samples confirmed earlier conclusions on the sensitivity of the formation to aqueous wellbore fluids (brine). The results also confirmed the stability of the perforation tunnels at high underbalance. An underbalance value of 1000 psi used in the outcrop sample tests indicated near zero perforation skin. Perforation strategy for the North Sea field was chosen based on the results from the study. Well performance analyses of 12 of the wells completed indicate low to negative skins. The information is presented in this paper as a case of how to design a good perforating job and also to emphasize the need to study optimum underbalance for gas formations.
Application of a New Measurement Technique for Organic Acid Additives in Stimulation Fluids
Authors: Taylor K. C. , Al-Katheeri M. I. , Nasr-El-Din H. A. , Ahmed I. 
Published: December 2007

Abstract
An analytical method was implemented to simultaneously measure the concentrations of acetic, citric and formic acids in stimulation fluids. This method was not previously available for acid stimulation treatments. Capillary electrophoresis is used for rapid and accurate measurement of these organic acids in concentrated hydrochloric acid and in highly contaminated spent acidizing fluids. Commonly used titration methods are not effective at low organic acid concentrations or when more than one organic acid is present. Acetic, citric and formic acids have been used extensively in Saudi Aramco fields over the last few years as stimulation fluids and as acid additives. Citric and acetic acids are frequently used in acid treatments as iron control agents.
The following conclusions are made: A method for the simultaneous measurement of acetic acid, citric acid and formic acid was developed and evaluated.The method is linear in the range of 2 to 200 mg/l of organic acid in diluted samples. Field samples will normally be diluted by a factor of 200 to provide a range of 0.02 to 2.0 wt% of organic acid.The method can be used at concentrations from 200 to 1667 mg/l, but has a nonlinear response in this region.Sample requirement is less than 5 ml in most cases.Reproducibility of the method was excellent. Relative standard deviation of organic acid standards was less than 1% at 200 mg/l, less than 3% at 20 mg/l and less than 10% at 2 mg/l.The detection limits of the method are 0.25 mg/l for acetate, 0.4 mg/l for formate, and 1 mg/l for citrate, based on a signal to noise ratio of 3 to 1.For acetate and formate measurement, no interference occurred with chloride up to 1000 mg/l, calcium up to 565 mg/l, iron (II) or iron (III) up to 500 mg/l, or sulfate up to 859 mg/l.For citrate measurement, no interference occurred with chloride up to 1000 mg/l, calcium up to 350 mg/l, or sulfate up to 859 mg/l. Iron (II) and iron (III) caused interference at concentrations of 10 mg/l.
The method was used to simultaneously measure organic acid concentrations in coreflood samples and in field samples from acid stimulation treatments.
Successful High-Pressure/High-Temperature Acidizing With In-Situ Crosslinked Acid Diversion
Authors: Buijse M. , Maier R. , Casero A. , Fornasari S. 
Published: December 2007

Abstract
This paper describes a very successful acid stimulation treatment performed in AGIP’s Trecate-Villafortuna Field. The matrix acidizing treatment used in-situ crosslinked acid (ICA) as the diverting agent. The treatment is unique because it represents the highest temperature application ever attempted for such a system and falls under the definition of high-pressure high-temperature (HPHT).
The design process included temperature simulations, detailed laboratory testing, and a review of acid formulations that were used successfully in the Trecate-Villafortuna Field and elsewhere. Temperature simulations indicated that cooldown from the bottomhole temperature (BHT) of 180°C to at least 150°C could be achieved despite the high treating pressures that limited injection rates. Even after cooldown, serious concerns about corrosion and the effectiveness of the ICA system still existed. Laboratory support included fluid optimization for high-temperature application of the ICA. The flow tests enabled the selection of the most appropriate base acid systems and demonstrated that the ICA system would indeed function at the predicted high temperatures.
Success of the treatment must also be attributed to the operational planning and close attention to experience gained from previous stimulation treatments. The execution of the treatment used all of the components considered to be state-ofthe-art in matrix acidizing treatment execution and evaluation: prestimulation injection tests, spotting of acid with coiled tubing (CT) to help reduce injection pressures and improve zonal coverage, the use of the Maximum Pressure Maximum Rate Diversion Technique (MAPDIR), and real-time treatment pressure monitoring.
The paper will present job procedures and a detailed treatment pressure analysis. It will also give details on the changes in injectivity and the Productivity Index (PI) before and after stimulation.
Gas-Well Dewatering: A Coordinated Approach
Authors: Stephenson G. B. , Rouen R. P. , Rosenzweig M. H. 
Published: December 2007

Abstract
A joint fieldwide study was conducted by a service company and exploration company to determine the optimum method of unloading gas wells in which production was limited by accumulation of liquids in the tubing. Various methods of unloading the wells were analyzed and compared. After evaluating different techniques, gas lift was determined to be the most effective and economical means of dewatering. Each well's characteristics were analyzed to determine the gains that could be achieved through continuous unloading. The analysis also identified the key wells that would benefit substantially from artificial lift and defined the system requirements necessary to place these wells on gas lift. After establishing the wells' performance characteristics, a full-system model was constructed. The model was used to evaluate the impact of the gathering and compression systems on the overall optimization and development of the field. Two scenarios were examined to determine the optimum configuration of the gathering system, compressors and injection lines. A gas lift distribution system was designed and evaluated for both cases. Finally, an economic analysis was performed for each scenario to determine the most cost-effective method of developing a dewatering system for the field.
Analysis of Well Tests in Multiple Fractured Reservoirs - Field Case Applications
Authors: de Swaan A. 
Published: December 2007

Abstract
A simplified analytical model of pressure transients in fractured reservoirs with matrix-rock blocks of different sizes and/or properties was formulated and applied to field cases. In the applications, relations between traits in the pressure vs. time plots and rock properties are used to determine rock block sizes and block-size distributions from actual well tests.

Introduction
The mathematical description of flow in fractured reservoirs with rock-blocks of different properties has been an obvious development after the models of media with a single type of block. References 1 to 6 present such models. However, these papers present involved formulations of the block-to-fracture flow. As a result their application in the analysis of actual well tests is not straightforward.
Flow in fractured media is accurately represented as flow in the connected fractures medium plus a block-to-fracture component that depends on the blocks, or matrix, properties. In the present paper a simple formulation of such block-fracture interaction as presented in previous papers7,8 describing flow in single block fractured media is extended to the case with multiple rock blocks.

Theory
For multiple-block fractured media the interaction of blocks and fractures is governed by the relative frequency of occurrence (or just frequency) of a block type in the pay and by the block properties included in the block function of flow. The flow equation in radial (cylindrical) geometry with a multiple block to fracture interaction term is1,Equation 1
The Laplace transform of the former equation is,Equation 2
Block's function of flow.
The flow from or into blocks is described approximately by an exponential function, see Ref. 8, for a unit pressure variation at the blok's surface.Equation 3
or, in the Laplace domain,Equation 4
a is the ratio of block surface to block volume divided by a fraction of the block minimal dimension8,Equation 5
the value of a for other parallelepiped shapes, such as prisms or finite slabs, have values intermediate between the two values shown in Eq. 5.
The block function of flow reproduces closely results of exact functions of flow from parallelepipeds; but it is simple for computations and also for linking block properties to traits in the plots of transient pressure response vs. time.
Block's function of flow.
The flow from or into blocks is described approximately by an exponential function, see Ref. 8, for a unit pressure variation at the blok's surface.Equation 3
or, in the Laplace domain,Equation 4
a is the ratio of block surface to block volume divided by a fraction of the block minimal dimension8,Equation 5
the value of a for other parallelepiped shapes, such as prisms or finite slabs, have values intermediate between the two values shown in Eq. 5.
The block function of flow reproduces closely results of exact functions of flow from parallelepipeds; but it is simple for computations and also for linking block properties to traits in the plots of transient pressure response vs. time.
Expandable Liner Hanger Provides Cost-Effective Alternative Solution
Authors: Lohoefer C. Lee , Mathis Ben , Brisco David , Waddell Kevin , Ring Lev , York Patrick 
Published: December 2007

Abstract
Establishing and maintaining hydraulic integrity between liner hangers and the base casing in which they are set has long been one of the most problematic areas facing operators. With failure rates on pressure seals in overlaps now exceeding 40% in some regions, the need for a solution to this decades-old problem has reached a critical level. Although new approaches have included turbolizers for cementing overlaps, special cements, and liner-top packers, many problems still remain.
An operator and a service company are working together to develop a new drill liner hanger based on patented expandable-casing technology. This technology is being used to diametrically expand solid tubulars for a variety of drilling, completion, and remedial applications. The new liner system is designed to totally eliminate the liner lap by expanding an elastomer-coated casing into intimate contact with the casing from which the liner is being hung. Preliminary results indicate the new hanger design can result in load-carrying and burst capacities that exceed the capacity of the previous casing string. Furthermore, the overlap samples tested to date have all resulted in annular seals that have exceeded 10,000-psi differential capacities. In fact, casing has always failed during large-scale testing before any overlap leaks developed.
This paper discusses the design and application of the new liner hanger and presents laboratory and field-test results.
Foam Diversion Modeling Using a Bubble-Population Correlation.
Authors: Bertin H. J. 
Published: December 2007

Abstract
In a stratified porous medium, foam can divert the flow from high permeability to low permeability layers. This interesting behavior found several practical applications in some reservoirs and aquifers. Moreover, experimental results have shown that foam blocking effect is maximum when the layers are isolated, i. e., when there is no capillary crossflow. Foam blocking in high permeability layers can be explained through the concept of limiting capillary pressure, Pc*, which is the maximum value of capillary pressure above which liquid films separating bubbles are broken.
In this study, we present a numerical simulation of foam displacement in a stratified system made of two noncommunicating layers with a permeability ratio of 5.4.
Numerical simulations are performed using a bubble-population correlation that allows us to compute explicitly foam texture in each layer from the physical properties of the rock (porosity, permeability and capillary pressure). We observe clearly the blocking effect of foam in high permeability layer, diverting gas to low permeability layer, due to capillary pressure difference.
Numerical results are qualitatively in good accordance with experimental data published in the literature.