bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Surface Hole Air-Foam Drilling Performance in Karstified Limestone (Papua New Guinea)
Authors: Zreik A. , Pinkstone H. , Ross A. 
Published: February 2011

Abstract
Drilling in The Highlands of Papua New Guinea is very challenging. The surface topography is extremely mountainous, with deep gorges and razoiback ridges. In addition, the Darai Limestone outcrops at surface and is karstified to a depth often in excess of 1,500 m, with the presence of underground rivers and caverns being common. The subsurface geology is even more complex with steeply dipping formations (at times near vertical), faults, and inverted sequences where the geological strata have been overturned by folding.
Well pads are constructed by flattening off the top of a mountain ridge or peak. Drilling from these elevated locations provides additional hydrostatic head to reduce the mud weight required in high-pressure formations encountered deeper in the well. Well pad construction is extremely costly but is more economic from peaks than from valley bottoms. Valley bottom locations often do not provide sufficient hydrostatic pressure head to maintain well control in deep, high-pressure formations without having to use excessively high mud weights.
The Darai Limestone is drilled with an air-foam mixture, as 100% lost circulation is typical. The karstification of this formation makes it unstable and prone to rubble collapse and mobile sediment packoffs.
An Overview of Completion Design for Vietnam Offshore Development Projects
Authors: Hay Bill , Lim Benjamin 
Published: February 2011

Abstract
The production completions in the Vietnam offshore arena are quite varied and most completion design philosophies are driven by the structure and the lithology of the production formation. This paper gives an overview of the various completion types in Vietnam offshore development projects, particularly those in the Cuu Long basin. Some variations of the completion philosophy are discussed in the paper such as the Miocene-type completions versus basement-type limestone completions. The completion design with respect to the production zones in the reservoir, the equipment selection criteria, and the other completion design mechanics will be reviewed in this paper.
The authors will also review some cased-hole completions design and discuss the functionality of the applications. The purpose of this paper is mainly to review the current applications. Additionally, completion design and philosophy would be examined as well as potential enhancements and future developments.
Lunskoye Offshore Gas Development—How Technology Made Development of This Large Gas Field Under Harsh Sub-Arctic Conditions Possible
Authors: van der Horst Juun , Webers Jeroen , Brown David , Zerbst Christoph , Muir Phil , Connon Bill , Purvis Travis 
Published: February 2011

Abstract
The development of the Lunskoye gas field is the centerpiece of the Sakhalin-2 project. The field is located offshore Sakhalin Island. The field was discovered in 1984 and was appraised by seven wells drilled from a mobile rig confirming a large gas accumulation. The Lunskoye-A (LUN-A) platform with limited offshore processing facilities was installed in 2006. Onshore Processing Facility (OPF) for the Lunskoye gas/condensate, offshore and onshore pipelines, a Liquefied Natural Gas (LNG) plant and oil and gas export terminals were completed and ready for operations in 2008 (Figure 1). Challenges that had to be overcome during the construction work were the lack of infrastructure, the seismically active area and the presence of rich onshore and offshore wildlife. Harsh, arctic like conditions such as temperatures as low as -40 degree C and long offshore ice periods from December till June, make it an extremely difficult environment to operate. Development drilling from LUN-A commenced in late 2007 and the first six gas producers were successfully completed on time to deliver the required contractual peak 2010 winter gas capacity of approximately 1.7 Bscf/d to the LNG plant. Lunskoye also produces up to 50,000 bbl of condensate per day. The fully integrated production system from the LUN-A wells to the LNG plant showed a smooth start up from early 2009 despite the many challenges and a very tight schedule.
Figure 1 Lunskoye Location map
After the completion of the 7th gas well in July 2010 the cumulative well capacity reached 2.3 Bscf/d or 330 MMscf /d per well on average. Two of the wells are 9 5/8 inch monobore gas completions with a world class potential deliverability of more than 500 MMscf/d. Development drilling is expected to continue uninterrupted until 2015 to maintain gas capacity and to develop the oil rim.
Modeling Miscible Injection in Fractured Porous Media using Non-classical Simulation Approaches
Authors: Stalgorova E. , Babadagli T. 
Published: February 2011

Abstract
The objective of this paper is to introduce an adaptation of a non-classical simulation method (random walk, RW) for simulation of fully miscible displacement in fractured porous media, and to validate this method using production and visual data obtained from an experimental work.
First, the limitations of classical (continuum models) modeling approach in the simulation of miscible displacement in fractured media were identified by matching the numerical and experimental results obtained earlier. Classical simulation yielded reasonable matches for low viscosity oil but failed to capture the flow patterns of heavy oil displacement, especially in the cases of vertical displacement. This was attributed to two reasons: (1) Numerical dispersion and grid size limitations and (2) the random nature of the phenomenon (mainly the viscous fingering process). Beyond that, the classical modeling scheme required the intensive use of "matrix-fracture pseudo transfer parameters" to achieve experimental matching.
To overcome these problems, a non-classical modeling approach, the Random Walk (RW) model was adapted. This technique deals with particles (walkers), each of which moves randomly, but the probability of the movement is defined considering the physics of the process. By tracing a large number of particles, one can model the process and have an idea about the transport of injected and displaced fluid in complex systems. The RW technique allows capturing micro heterogeneities, the random nature of the diffusion process and viscous fingering. It also requires less computational time compared to classical simulation methods.
The RW model introduced was validated using experimental -visual- data for different oil types, displacement directions (horizontal and vertical), and injection rates. This exercise showed that the model presented here captures the physics of the process and hence, can be extended and used for larger (field) scale processes of miscible displacement in complex fracture networks, which would not be possible with classical finite-difference models.
Real-Time Wellbore-Drilling Instability in Naturally Fractured Rock Formations with Field Applications
Authors: Nguyen Vinh X. , Abousleiman Younane N. 
Published: February 2011

Abstract
Overcoming wellbore drilling instability in fractured-rock formations always presents one of the major challenges to drilling engineers. Due to different fluid-diffusion rates and compressibility degrees between the rock’s matrix and fracture network, there are two distinct pore-pressure fields and subsequently different effective stresses developed in a saturated fractured formation. It is recognized that wellbore instabilities such as collapses are caused by excessive effective stress concentrations at or near the borehole wall, and mud losses are due to fracturing the rock formation. Because both the mud/rock fluid-pressure differential and fractures’ deformation modify the effective stresses in the wellbore wall, such intricate responses require a wellbore solution that accounts for the fracture network, intact rock matrix mechanics, and the balance of drilling mud density. In this work, the effects on real-time collapse and fracture gradients that dictate the safe mud weight window are evaluated analytically, incorporating the effects of natural fracture network via a simulated field case. Analyses reveal that neglecting the naturally fractured nature of the formation falls short in simulating the wellbore instability since it predicted a narrower mud weight window for the drilling operation.
Design of “Anti Surge” Methodology to Mitigate Severe Lost Circulation While Running Non Conventional Casing / Liner Sizes to Isolate Salt and Clay Domes in Deep Wells in Mexico South
Authors: Orellan Sael , May Richard , Bedino Henry , Atencio Nixklafe , Diaz Lenin , Martinez Alfonso , Tellez Carlos Perez 
Published: February 2011

Abstract
A typical well scheme for a deep well usually has five casing sections that can include a liner string. However the number of casing strings is given by the number of intermediate sections required to isolate unstable formations prior to reach the pay zone.
The industry has defined the casing sizes following a standard well design of five casing string (Table 2) that can include liners depending on the well requirements. The clearance between casing string is based on a standard drift which is related to unobstructed tolerance through pipes that is associate to the casing geometry such us ovality and casing straightness, this design criteria does not take in account other phenomenons that can compromise the effectiveness of a well design such us the effect of surges forces while running casing strings.
In prescence of competent formations and shallow wells, the design citeria explained above does not represent risk in term of loss circulation during running casing or cementing operations. However in the Mezosoic fields at Souht of Mexico (Figure 1), the geological structures are domain by unstables clay domes and eventually salt domes (Figure 2) that are located between 3,200 m - 3,700m. Also the drilling environment is characterized by narrow mud windown. As a consequence the wells are completed with six casing string.
The wells drilled in this fields are classified as high risk wells due to the potential hole problems related that include massive lost circulation. The geometry of the wells is also an issue since the use of non conventional casing sizes to isolate unstable formations left low clearance between casing strings that induce lost circulation when running casing.
This paper describes the actions taken to reduce massive loss circulation and define an “Anti surge methodology to mitigate severe loss circulation” when running non-conventional casing sizes with reduced clearance between casing strings in some fields located at South of Mexico.
Methods of Multiple-Point Statistics in Geological Simulation Practice: Prospects for Application
Authors: Bezrukov A.V. , Davletova A.R. 
Published: February 2011

Abstract
The conventional methods of two-point statistics (TPS) applied in geological simulation have preserved histograms and variograms. However, they have serious limitations in creating complex reliable distributions of geological bodies. Multiplepoint statistics (MPS) methods enable solving a wider spectrum of geological simulation problems while also preserving the common statistical parameters. However, the application of these methods in practice is complicated by the requirement of reliable litho-facial models and the corresponding training images. A possible solution could be the development of a library of training images (TI) to cover the variety of sedimentation environments and a wide distribution of statistical parameters in geo models. The selection of training images and their scales for specific simulation tasks is based on matching statistical parameters; the simulation result in this case inherits these parameters. This approach ensures the match in general statistical parameters of the models created using TPS and MPS. However, the difference in higher-order distributions may affect flow model properties.
In this paper, we investigate some issues of implementing MPS methods, developing a training image library, as well as selecting and scaling TIs. Some comparison results between TPS and MPS models are presented.
Technological Solutions for Marginal Oil Fields Development
Authors: Ibatullin Ravil R. , Takhautdinov Shafagat F. , Ibragimov Nail G. , Khisamov Rais S. 
Published: February 2011

Abstract
The long-term oil development projects in the Volga-Ural region are associated with depleted reservoirs. TATNEFT fields with 80% reserves depletion level produce 16.2 million tons of oil; fields with 70-80 % reserves depletion produce 4.4 million tons out of 25.8 million tons of total production.
Profitable oil production of TATNEFT fields is challenged by highly depleted reservoirs of Romashkinskoye, Bavlinskoye, Sabanchinskoye, Novo-Elkhovskoye, Pervomayskoye, and Bonduzhskoye fields. TATNEFT has developed a suite of technological options for marginal oil field development. 1.Reservoir engineering management, efficient development of depleted fields.Based on the analysis data TATNEFT specialists have selected and approved screening criteria for up to 50 different EOR techniques.Annual incremental oil production due to water-flooding management and application of EOR techniques exceeds 11.6 mln tons, including 5.1 mln tons due to tertiary recovery (about 20% of total production) and 6.5 mln tons due to water-flooding (25%).2.Efficient oil production technologiesChain-drive pumping systems with 3-m and 6-m stroke length have been implemented in TATNEFT assets since 2002, and by the end of 2009, their number totaled to 1113. The systems show maximum efficiency in heavy oil wells and wells with emulsion-related problems, reducing specific energy consumption by up to 60%.Dual-completion systems find wide application in the development of new targets in marginal wells. This paper presents modified dual-completion systems deployed in 533 wells. Incremental oil production due to these systems has exceeded 1 million tons. A dual-injection technology was developed in 2007, and to date dual-injection systems have been deployed in 128 injectors. The new technology yielded 170 200 tons of cumulative incremental oil production.The overall operational benefit is the reduction of specific energy consumption per 1 ton of produced oil. In 2009 it made 119 kwh/ton, which is 4.7% lower as compared to 1998.
An Integrated System for Improving Geotechnical Performances of Jackup Rig Installation
Authors: Quah M. , Cahyadi J. , Purwana O. A. , Krisdani H. , Randolph M. F. 
Published: February 2011

Abstract
Predictability and consequential safety of jackup rigs during installation and removal remain non-trivial issues for the industry despite larger deployment of jackup rigs and operations in emerging frontier regions with more complex soil conditions. Jackup foundation hazards such as unpredicted leg penetration, rapid leg penetration, punch-through, spudcan-footprint interaction and leg extraction difficulties continue to occur in spite of the industry stepping up efforts to better control of the risks. Apart from improvements of the installation guideline and practice within the industry as well as implementation of proper site specific assessments, safer performance of jackup rigs may be achieved through advancement in jackup instrumentation technology. In the present paper, a new instrumentation technology integrated with jackup rigs is proposed to assist the jackup operators in making decision and taking measures to prevent or mitigate potential geotechnical hazards, particularly punch-through.
Petrophysical Invariance Principle in Adaptive Well Log Interpretation
Authors: Kozhevnikov D. , Kovalenko K. 
Published: February 2011

Abstract
The adaptive interpretation technique developed which allows of significantly reducing the number of error sources and improving accuracy, reliability and informativmess of the well logging results.
The existing conventional interpretation technology of the well logging data in comparison with adaptive one has a lot of uncertainties because of the information deficit about petrophysical and petrochemical characteristics of the mineral components and other factors affecting measurements.
The well logging data interpretation is basically focused on definition of porosity in studying of oil and gas reservoirs. But for the complex reservoirs porosity has appeared to be a misinformation parameter: the reservoir rock with high porosity may fail to possess effective porosity that is it may not be a reservoir. It is necessary to consider a corresponding petrophysical model to substantiate effective (and dynamic) porosity as a direct interpretative parameter of the well logs.
It is possible to introduce an alternative adaptive interpretation for the effective porosity evaluation. The adaptive interpretation is based on the petrophysical invariance of the reservoir and is using the petrophysical invariant as the main interpretation parameter.
The way how the petrophysical invariant can be calculated directly from the well logging data established. It is shown that different well logs can be used for the effective porosity evaluation.
The adaptive technology advantages include: effective (dynamic) porosity can be calculated for the complex polymineral reservoirs in absolute units without “reference beds”; the technology provides adaptive tuning under lithological and petrochemical conditions of the particular reservoir in situ, including the wellbore construction influence; in contrast to the conventional interpretation the adaptive technology does not require any tools standardization; it can be used for the old data reinterpretation; the adaptive technology allows tuning in terms of particular tool metrological characteristics downhole.
Maintenance Service and Repair Chamber for Pipelines in Bogs and Under Water
Authors: Khasanov Ilmer 
Published: February 2011

Abstract
This work presents swamp and underwater oil pipeline maintenance and repair chambers. Assemblies of repair chambers are assigned for repairing of pipeline sections in the swamps, across the small lakes, former riverbeds and in the bottomland part of underwater passages without bringing them up to the surface. Demountable carrying structures are offered for transportation of technical equipment across swamps of all three types and delivering of repair chamber to the place of mounting. This design successfully passed field tests in the swamps of second type in Western Siberia.
New Coriolis Based Multiphase Flow Meter For Heavy Oil Mature Fields
Authors: Agar Jo 
Published: February 2011

Abstract
In many mature heavy-oil fields, production well-testing is limited by the ability of test separators to separate gas and water from heavy viscous oil. The new technology of multiphase metering addresses these issues through the use of a low cost, robust Multi-Phase Flow Meter (MPFM).
This paper describes the fundamentals and field tests of this low-cost, portable multiphase meter. The meter utilizes a new coriolis flow meter technology combined with a microwave-based water cut meter that can measure 0-100% water-cut in the 0-100% Gas Void Fraction (GVF) range. The combination of these technologies provides a light-weight metering package that can be mounted onto trailers and/or pick-up trucks for portable well testing.
This multiphase meter can measure oil, water and gas without separation of the production stream at low & high GORs (Gas-to-Oil Ratio). These applications can be found in mature fields where the conventional test separators are inefficient or under-sized for heavy oil applications. In these types of applications, a low-cost, accurate multiphase flow meter offers many benefits – one of which is accurate well test data for production optimization.
The multiphase meter was subjected to qualifying tests prior to deployment in oil fields in the U.S., Alberta, Canada, Surinam, Venezuela, Romania and other locations where heavy oil rules out conventional "Sputniks" and other type of gravity separators. The paper describes the new fundamentals of the patented technology showing actual test results.
A Saskatchewan Field Trial to Better Understand Downhole Dynamics of PCP Systems
Authors: Noonan S. G. , Studer D.. , Skoczylas P.. 
Published: February 2011

Abstract
This paper presents the results of a field trial conducted in Saskatchewan, Canada to investigate drive string dynamics between conventional and continuous rod and the impact of interference fit between rotor and stator in progressing cavity pumps (PCP).
In August 2009, a well was completed with a downhole monitoring system and a PCP driven by a continuous rod string. At the same time, a second well was completed with a downhole monitoring system and a PCP driven by a conventional rod string. The pumps were identical with the exception of the interference fit of the rotor in the elastomeric stator.
Thousands of data values were collected over a period of several months and evaluated to better understand rod stretch, torsion, and axial movement during start-up, shut-down and normal operating conditions and how these values change as a function of the interference fit of the pump itself. While the data evaluation did provide answers to help ConocoPhillips improve their PCP operations, there were even more questions generated that will prove thought-provoking to the industry and stir some great discussion.
Advances in Modeling of Passive Inflow Control Devices Help Optimizing Horizontal Well Completions
Authors: Ostrowski L. , Galimzyanov A. , Uelker E. B. 
Published: February 2011

Abstract
Passive Inflow Control Devices (PICD) has become a frequently used completion method for horizontal and close- to-horizontal wells over the past decade. There are several types of PICDs, but the working principle is similar for all of them: PICD restricts a flow by creating an additional pressure drop and therefore equalizing the wellbore pressure drop to accomplish a uniformly distributed flow along the horizontal well.
To evaluate performance and potential benefits of a PICD completion, a full-field simulation model is required. Simple near-wellbore simulators are often used to initially evaluate the applicability of the PICD-based completion. However, only full-field reservoir simulation can provide prediction for the completion/reservoir performance and thus allow for a full evaluation of the economics and feasibility of the project. A multi-segment well model can be used to represent the PICDs in the horizontal well. The multi-segment well model is an advanced well modeling that allows accurate modeling of multi-phase flow and pressure variations in wells with a reservoir simulation model.
This paper provides an example of the reservoir development study. PICD completion is designed and optimized to achieve the best possible economic results using in a commercial black oil simulator. The work is based both on a generic model. The methodology of implementing external pressure drop models is presented. Also, the process of optimization of the PICD-based horizontal well completions utilizing simulation is shown.