bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real Time Drilling Geomechanics: Successful Application in an Inclined Well in Ultra-Deepwater off East Coast of India
Authors: Kumar Devendra , Singh Hemant , Kumar Rajeev , Rao Dhiresh G. , Sundaram K. M. 
Published: October 2012

Abstract
Assurance of wellbore stability (WBS) is of utmost concern and a key challenge in drilling an inclined well in ultra deep water of the East Coast of India. The WBS analysis requires accurate modeling of earth stresses and rock mechanical properties. These processes are primarily based on sonic logs (compressional and shear slowness), bulk density and lithological distribution. To understand and address drilling complications in the study area, post-drill (offset well analysis) and real-time drilling geomechanics is carried out in this well.
1D mechanical earth model (MEM) and WBS model is constructed for offset wells, which is calibrated with caliper log, pressure test and leak-off data sets. WBS analysis suggested drilling with lower mud weight in the zones of shear failure and pack-off. Disparity in resistivity values is also observed when wireline logs and Logging-While-Drilling (LWD) logs are analyzed. This might be due to mud invasion or fluid-shale interaction in the open hole, as it is resolved by changing mud system from water based mud (WBM) to synthetic oil base mud (SOBM). The post-drill analysis of offsets wells established parameters for the upcoming inclined well.
The planned well is the first inclined well (horizontal drift more than ∼2000m) in ultra deepwater of the East Coast of India to avoid the drilling risks; real-time drilling geomechanics is first time put into operation. Required sonic and density data is received in reasonable time intervals to perform real-time analysis. Timely updates on rock mechanical properties are provided to client, which helped in optimizing drilling parameters. As a result, first inclined well in ultra deep water in the East Coast of India was drilled successfully.
Positive Psychology and the Company Man
Authors: Hase Stewart , Phin Simon 
Published: October 2012

Abstract
This discussion paper concerns the critical role leadership plays on safety behaviour in the innately hazardous environment of oil and gas installations. It has been demonstrated on a number of occasions that safety culture is a major determinant of either positive or negative safety behaviour. In turn it is clear that managers at all levels on a rig can determine the safety culture though the emphasis they place on safety in all that they do. It has also been shown that transformational and transactional leadership styles are much more effective in developing a positive safety culture than authoritarian and passive styles. Positive psychology is a relatively new concept in psychology that emphasises an optimistic view of people and the world, of possibilities and what can be done. The approach provides a number of easily learned techniques that can improve leadership style and safety culture as part of the essential war on fatalities and injuries.
New Practices for Cement Integrity Evaluation in the Complex Environment of Xinjiang Oil Field
Authors: Hongzhi Guo , Guobin Wang , Zhi Wang 
Published: October 2012

Abstract
Junggar basin in west China is rich in oil and gas reserves in different geological structures that range in depth from 800 m to 7000 m. A variety of cement slurries is used to ensure the cement integrity in the wells. For instance, low-density cement as light as 1.1 g/cm3 with hollow glass microspheres has been used for low-pressure-gradient formations in long openhole wellbores, whereas high-density cement as heavy as 2.5 g/cm3 with iron mineral powder and other additives has been applied in high-pressure deep wells. This variety poses challenges to performing cement evaluation with traditional acoustic techniques that have limitations in providing unambiguous answers, and in some instances it is not possible to assess implications to zonal isolation behind casing.
A new-generation ultrasonic imaging tool was deployed to increase the confidence in cement evaluation in Xinjiang oil field over the past 2 years. This technique combines the traditional pulse-echo ultrasonic measurement with a new flexural wave measurement. The analysis allows a better discrimination of solid, liquid and gas for density-independent cement evaluation behind casing, additional information on casing centering, annulus geometry, and accurate casing inspection at high resolution in one logging trip. Based on this improved zonal isolation information, well testing design improved, and the testing success rate was significantly increased over previous operations. Moreover, the cementing technique improved from proper post evaluation. The examples in this paper demonstrate the value of the high-quality logging data that were acquired in different downhole conditions. This paper presents a new way to look at cement quality and placement.
Artificial Neural Networks for Corrosion Rate Prediction in Gas Pipelines
Authors: Supriyatman Deden , Sumarni Sumarni , Sidarto Kuntjoro Adji , Suratman Rochim 
Published: October 2012

ABSTRACT
Artificial Neural Network (ANN) is adopted from the human neural network systems and is among many tools to understand complex model including corrosion. Such predictive model can be developed through corrosion rate. By ANN application, one may update its model iteratively, hence it will be adaptable for all decisions. It can be learned from the previous data and recognize patterns of data always changing and dynamic, like the ones in oil and gas fields.
Based on the characteristics of ANN methods, corrosion rate model will update iteratively during the training phase leading to the best (more accurate) model target. Using a number of data input and output characteristics of the fluid, the result of corrosion rate model will be able to predict the corrosion rate in the range of the entered input data. With models that are adaptive and can adjust to changes in the dynamic data, one will be able to obtain predictions with a great degree of accuracy.
Research methodology on the subject using crude oil was developed by Hernandez and Nesic (2005). Some crude oil characteristic associated with the corrosion rate are, among others, sulfur, vanadium, nickel contents, total acid number and API. A correlation analysis between the crude oil characteristics vs corrosion rate, then a regression model of percentage of inhibiton which is a function of characteristics of crude oil were obtained. Percentage of inhibition in this regard is the number of ratio between the corrosion rate of the fluid-carrying pipe and corrosion rate in the blank pipe.
This paper will describe ANN that creates a program to determine the corrosion rates of the carbon-steel materials containing flowing fluid (gas). The characteristics evaluated are gas composition, temperature and pressure then regression equation of inhibition percentage will be made in the characteristics function of earlier inputs. Only data having a high level of significance will be used, and the ones of very low level of significances will be excluded in the equation. The next step is building models with ANN for which significant data based on the regression test will be used as input data to the corrosion prediction program in gas pipelines.
The deliverable of this study is getting the prediction program of gas pipeline corrosion of carbon steel using MATLAB software. The program accuracy of the program is compared with the actual data.
Simulation of Formation Damage after Long Term Water Flooding
Authors: He Liu , Guoxin Li , Yiliang Li 
Published: October 2012

Abstract
Water flooding is a commonly used technology for enhancing oil recovery. Its mechanism is to maintain higher pressure in reservoir and to sweep the oil from the reservoir and push it towards production wells. However the strong water flooding will cause higher compression pressure around the injection wellbore. This high pressure in the reservoir causes stress redistribution and higher stress near the wellbore which induces material damage and permeability change. We developed a fluid-solid coupling finite element model to simulate and quantitatively analyze the pressure evolution in the reservoir as well as damage and permeability change in the formation during long term water flooding process. The obtained results offer theoretical understanding on the benefits (pore pressure increase in the simulation domain), rock damage, permeability change of long term water flooding and the insights of how to detect and prevent wellbore failure and collapse due to water flooding.
Direct Averaging Estimates of Separate Zone Production in Gas Wells Based on Pressure and Temperature Profiles
Authors: Barrett E. , Abbasy I. , Wu C.-R. , You Z. , Bedrikovetsky P. 
Published: October 2012

Abstract
Accurate and reliable flow rate estimation along the wellbore plays an important role in reservoir development and production management. Traditional methods are expensive, particularly in high temperature wells; and they usually involve running production logsging tools (PLT) together with flowmeters. Deployment of PLTs into a well can be operationally difficult and typically requires flow to be suspended temporarily to allow the tools to be run in hole. This can have a negative impact on the quality of data collected, potentially making it un-representative of normal producing conditions. Alternatively, a simple direct averaging method of the gas flow rate estimation from temperature and pressure data is proposed in this paper, compared to the iterative approach. Solution of the inverse problem allows predicting the flow rate and formation thermal conductivity by matching the gas pressure and temperature profiles with field data. The results of data treatment show good agreement with the model prediction and are consistent with flowmeter (PLT) data, which validates the method developed in this work.
Stimulation of Natural Cleats for Gas Production From Coal Beds by Graded Proppant Injection
Authors: Bedrikovetsky P. , Keshavarz A. , Khanna A. , Kenzie K. M. , Kotousov A. 
Published: October 2012

Abstract
Graded injection of proppant particles with increasing size and decreasing concentration, proposed in the previous paper results in deep percolation of proppant into the natural fracture system, expansion of the stimulated zone and enhanced well productivity index. The mathematical model developed describes the proppant-free water injection stage, the capture kinetics of proppant particles in the natural fractures and the change in well index due to graded proppant injection. Computational fluid dynamics and classical Hertz theory have been used to determine the hydraulic resistance due to proppant plugging in the fracture system and the deformation of fractures during the production stage.
An optimal injection schedule, i.e. the timely dependence of the injected proppant size and concentration that avoids fracture closure during production stage and provides minimum hydraulic resistance in the system of fractures plugged by proppant particles has been developed. The model is used to predict the change in well productivity index allowing estimating the feasibility of the graded particle injection for well stimulation in natural fractured systems.
The aim of the current paper is to analyse the feasibility of application of the proposed graded proppant injection method for stimulation of the natural fracture system in 3 field cases of large coal bed methane reservoirs.
Fracture Growth and Injectivity Issues for Produced Water Reinjection Wells - Case Studies with Fields from Australia and the UK North Sea
Authors: Rahman Khalil , Khaksar Abbas 
Published: October 2012

Abstract
Produced water reinjection is gradually becoming a preferable option for water disposal because of increasing stringent environmental regulations. During long-term injection, a fracture usually initiates from the injection well and then grows deep into the formation. The growth of this fracture and the long-term injectivity are mainly influenced by formation properties, solids loading in water, in-situ stresses and well trajectory. Fracture growth and injectivity during produced water reinjection are influenced by long-term leak-off processes, thermo-poroelastic changes within the formation and the intermittent injection nature.
This paper presents an approach for systematic considerations of critical issues that greatly influence the well trajectory, completion, fracture growth and long-term injectivity. The approach was applied recently to two field cases for planning and decision-making: one field in Australia and the other field in the UK North Sea. The effects of the following issues on fracture growth and injectivity were addressed in the North Sea field case: in-situ stress magnitudes and direction; thermo-poro-elasticity; solids loading; perforations, tubing strength and pump capacity; and operational issues to maintain injectivity. Although the above issues were common to the Australia case, the special challenge came from high solids loading in water requiring a very large fracture to store solids particles.
Highlights of the study results include (1) potential fracture growth complexity and injectivity loss, (2) high pressure loss requiring high pump capacity, (3) undesirable fracture growth risking well completion and surrounding structures, and (4) fracture tip plugging by formation debris during intermittent injection. Mitigation strategies for all these complexities are also addressed in the paper.
The paper will guide engineers when addressing geomechanical, fracture growth and injectivity issues at the planning and designing stages of a produced water reinjection well.
Best Practices in Developing Deep Tight Gas Reservoirs for Maximum Recovery, Sultanat of Oman
Authors: Busaidi R. , Diamond L. , Mugheiry S. , Abri Z. , Rendon J. , Lukmanov R. 
Published: October 2012

Abstract
The Main Sultanat of Oman Gas Field is comprised of two deep tight gas clastic reservoirs, separated by thick shale layer, and has been on production since 1999. These reservoirs are encountered at depth ranges of 14,000 - 17,000 ft and the top reservoir is a rich gas condensate followed by a lean gas for the lower reservoir. Permeability is in the range of 0.01 to 10 mD, porosities of 1 % to 14% and this field being a swing producer, actual production is in the range of 700 - 1,000 MMsfcd.
To ensure achieving a maximum value, from such complex reservoirs, the field has gone through several development stages. The first stage has focused mainly on appraisal and development wells to obtain better understanding of well and reservoir performance and further data acquisition for better reservoir characterisation.
The second stage of the Field Development Plan (FDP), in 2005, was an update of the FDP reflecting all the information that have become available since the commission of the field as well as the production performance gained from the previous 5 years of production. Further optimization of total number of wells, better prediction of the field performance and firming up the first stage of depletion compression were the key elements of the FDP update. Hence, first stage depletion compression plant was pursued and commissioned in 2010. In addition, velocity strings from 51/2" to 27/8", for maximum utilisation of low producing wells, were evaluated and more appraisals activities, for further scope maturation, were assigned.
The third stage of the FDP update has been completed. The key objectives were to validate the previous FDP, in particular, wells and reservoir performance as a result of stage-1 depletion compression. Besides, phase-2 depletion compression was proposed and the remaining development drilling were re-evaluated, optimised and confirmed.
Furthermore, a plan to mature contingency reserves, from poor reservoir intervals, was initiated and associated studies, such as geomechanical models and fracturing optimisation were performed.
In this paper, a case study of developing a complex and tight deep gas reservoir will be discussed. The experience of applying phase approach and associated value will be shared and how the multidisciplinary team came up with the best Field Development Plan taking into consideration the different challenges and options taken by every discipline to put the best development strategy to get the optimum ultimate recovery from the field.
An Innovative Static Modeling Approach to handle a Complex Giant Mature Field within a Compressed Timeframe; A Case Study of the Baram Oil Field, Offshore Sarawak, East Malaysia
Authors: Latief Agus Izudin , Ridzuan Ahmad Idriszuldin , Faehrmann Paul Andrew , MacDonald Alister , Nasir Wardah Arina , Rahman Gozali , Rahman Mohd Elzrey 
Published: October 2012

Abstract
Baram is a giant mature field situated, offshore Sarawak Malaysia. Reservoirs consist of an approximately 7000 ft thick-stacked sequence of shallow marine sands, distributed in excess of 200 zones. The field is extensively faulted. Early Growth faulting followed by a later compressional phase has led to complex fault geometries. The field has been producing for over 40 years and presently has 175 wells.
Although the reservoirs are generally of good quality, the field currently has relatively low production rates, a low recovery factor, and a significant amount of remaining reserves. The geological complexity poses a key challenge, and a robust static reservoir model is a prerequisite for efficient reservoir management and for identifying viable Improved Oil Recovery (IOR) measures.
Static models of the Baram field had previously been constructed. This modelling took in excess two years to complete and the models were segmented into 10 pieces, as technology during this period was unable to tackle complex fault geometries. Due to the results of the static / dynamic modelling being insufficiently robust when tested during a drilling campaign in 2009, the decision was made to remodel.
The Baram subsurface team was challenged with building a static model which could be used for field management and IOR/EOR process selection and optimization within a six month timeframe. This is to allow for early investment decisions and an accelerated reversal of production decline. The key aspects of the fixed timeframe static model construction are described below. They consist of:
The subdivision of the field into independent models. The utilization of a modern algorithm to model complex fault geometry. Nested stratigraphic modeling. Parallel property modeling and the re-combining of results into a single simulation grid to enable integrated reservoir simulation.
A full focus on the importance of the timeline and early investment, plus the adoption of a variety of strategic project management measures and use of "state of the art" modeling technology can allow fit-for-purpose static models to be delivered on time.
Simulation of Multiphase Fluid-Hammer Effects during Well Shut-In and Opening
Authors: Han Guoqing , Ling Kegang , Khor Siew Hiang , Zhang He , Company Ryder Scott , Thakur Ram Kinkar 
Published: October 2012

Abstract
In this study, a transient multiphase simulator has been used to characterize the fluid-hammer effects of well shut-in and start-up on the coupled subsurface and surface systems. The original work was performed by applying sensitivity analysis on a typical production system that includes well completion, wellbore, downhole equipment like packer etc., and the associated surface equipment like flowline, riser and valves. The data used in the study was taken from the published literature to summarize the general course of key factors that worsen the fluid-hammer effects. Fluid-hammer is also known as water hammer, a shock wave produced by the sudden stoppage or reduction in fluid flow.
Field operations such as pressure transient analysis, facility maintenance and workover require well shut-in process. For a typical production system, the resulted sudden rises in pressure can be critical because it has direct impact on equipment including unsetting of packer and may also cause possible damages to instrumentations. This paper provides estimates of the typical ratio of transient shock in pressure and flowrate over pre-condition values, and the duration of such pressure shocks. It also proposes the best location of the shut-in valve and the length of flowline to reduce the fluid-hammer effects.
This is a pioneering approach to integrate multiphase flow modeling of transient fluid-hammer effects, targeting flow assurance issues. This approach also can be applied to surface facility design and served as guidance in field operation to avoid hydrocarbon leaks.
Optimizing the Value of Reservoir Simulation through Quality-assured Initialization
Authors: Worthington Paul F. , Hattingh Shane K. 
Published: October 2012

Abstract
The initialization of a reservoir simulator calls for the populating of a three-dimensional dynamic grid-cell model using subsurface data and interrelational algorithms that have been synthesized to be fit for purpose. These prerequisites are rarely fully satisfied in practice. This paper sets out to strengthen initialization through four key thrusts. The first addresses representative data acquisition, which includes the key-well concept as a framework for the cost-effective incorporation of free-fluid porosity and permeability within an initialization database. The second concerns the preparation of these data and their products for populating the static and dynamic models. Important elements are dynamically-conditioned net-reservoir cut-offs, recognition of primary flow units, and establishing interpretative algorithms at the simulator grid-cell scale for application over net-reservoir zones. The third thrust is directed at the internal consistency of capillary character, relative permeability properties and petrophysically-derived hydrocarbon saturations over net reservoir. This exercise is central to the simulation function and it is an integral component of hydraulic data partitioning. The fourth concerns the handling of formation heterogeneity and anisotropy, especially from the standpoint of directional parametric averaging and interpretative algorithms. These matters have been synthesized into a workflow for optimizing the initialization of reservoir simulators. In so doing, a further important consideration is the selection of the appropriate procedures that are available within and specific to different software packages.
The implementation of these thrusts has demonstrably enhanced the authentication of reservoir simulators through more readily attainable history matches with less required tuning. This outcome is attributed to a more systematic initialization process with a lower risk of artefacts. Of course, these benefits feed through to more assured estimates of ultimate recovery and thence hydrocarbon reserves.