bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lateral Vibration Of Drill Pipe Including Wall Reaction
Authors: Hsu Feng-Hsiang , Wilhoit James C. 
Published: December 2007

Publication Rights Reserved

Abstract
The impact of a drill pipe on the wall of a borehole is treated as a time-dependent force acting laterally on the pipe assuming the existence of periodic motion. The impact force is estimated by Hertz theory of impact. The solution obtained must satisfy the constraint conditions to approximate the impact action.

Introduction
Transverse vibration of drill pipe is investigated here to yield some notion of the stresses induced in the pipe by the motion. The problem is highly non-linear in nature not only due to the non-uniformity of the drill string, inelasticity of the wall of the borehole, nonlinearity of the various forces induced by the presence of the non-Newtonian drilling mud, etc., and also due to the notion itself if the wall is replaced by a spring. From an engineering point of view, a simple model constructed by neglecting all the non-linearities due to materials will reveal some aspects of the effect on stresses due to motion alone.
Some similarities can be observed between the vibration of drill pipe and the simple one-dimensional mass-spring system with clearance if the elastic impact between pipe and wall is replaced by a non-linear spring [see Fig. 1]. In general, there is no assurance of the existence of a simple periodic motion even for the one-dimensional simple system if viscous damping is included and an arbitrary force is applied. However, under certain conditions, a simple periodic motion can be obtained. For instance, if the energy fed into the system is such that it balances the energy dissipation due to damping at any moment, then the system can be regarded as an undamped system. For such a system, a simple periodic motion with fixed mode does exist.
On the assumption that a prolonged periodic motion deserves more attention on account of the fatigue effect on the material, and also that a suitably constructed periodic motion serves as an average of some random or highly complicated notion over a certain range, this paper treats the case of simple periodic motion of the system. A sample section of pipe which vibrates in a fixed mode, between two adjacent nodal points, is isolated from the drill string. This sample section is considered as being simply supported. The impact is considered as a time dependent force acting laterally on the pipe. Thus the impact problem is changed to a forced vibration problem under the assumption of simple periodic motion. However, the solutions obtained from the forced vibration system must satisfy a set of constraint conditions in order to interpret it as the solution of the impact problem.

MATHEMATICAL MODEL AND EQUATION OF MOTION
If the drill string is considered as a uniform cylinder and the borehole is treated as a vertical straight hole, then the sample section and a typical pipe element can be regarded as shown in Fig. 1.
In Fig. 1, the lateral force term FL includes the impact force, the inertia force of the pipe and the inertia force of the fluid contained in the pipe.
Rama Reservoir Model Study
Authors: Kovacs P. P. 
Published: December 2007

Abstract
Although the Rama Field is known to have a large volume of oil·in-place, performance data indicate a relatively low primary recovery. PERTAMINA and IIAPCO jointly performed a reservoir model study to determine the potential for improving performance by supplementing primary recovery techniques now in effect. This paper provides a case study in the use of computer models to simulate a producing reservoir. The paper describes the development of the model and the manner in which it was used to gain a better understanding of the reservoir mechanics unique to the Rama Field. The study resulted in a more accurate assessment of primary recovery potential, and it defined the improvement in performance that can be expected through a program of infill drilling and secondary recovery techniques.
The Exploration Applications of Seismic DHI Analysis in the Malay Basin
Authors: Carson T G , Phipps G G 
Published: December 2007

Abstract
Over the last 15 years or so, improvements in reflection seismic acquisition, processing and interpretation methods have enabled the geophysicist to interpret the presence of hydrocarbons directly from seismic data. This is especially true in Tertiary clastic basins.
Success in predicting the presence of hydrocarbons on seismic data depends on the interpreter 's ability to recognize the effects they have on seismic reflections. These characteristic changes in reflection pattern are called direct hydrocarbon indicators or "DHFs" Under idealized conditions, DHI analysis can yield valuable exploration information concerning the presence, thickness, lateral limits and type of hydrocarbons present in a structure. Information concerning the presence, extent and seriousness of drilling hazards related to shallow gas can also sometimes be obtained.
EPMI geophysicists have been usig DHI analysis of seismic data to assist in locating and planning exploration and delineation wells in the Malay Basin. The degree of success of DHI predictions has varied markedly. The key factors that effect success have been data quality including near surface interference problems, bed thickness versus resolution restrictions, facies conditions including the presence or absence of coals, and low gas saturation. To date, a fairly high degree of success has been obtained in predicting the presence of hydrocarbons in non-coaly environments up to depths of about 7000'. Success in mapping the lateral limits of these recognized hydrocarbon zones usually depends on bed thickness and may be complicated by the potential presence of low gas saturation below the hydrocarbon/water contacts, In thick reservoir units it is sometimes possible to locate and map gas/ oil and oil/ water contacts thus providing the explorationist with a tool for recognizing and mapping the extent of different fluid systems in multi-reservoir fields.
Star: Shallow Time Anomaly Replacement
Authors: Marcoux Michael O. , Lu Lee 
Published: December 2007

Abstract
The presence of spatially varying low velocity thin layers in the near surface can account for the surface consistent terms in the description of reflection times. If the same low velocity material occurs at a greater depth in the section then its effect on reflections will vary with reflector depth. The dynamic characteristics of such a "buried static" feature is discussed and a subsurface consistent, time-variant static description is given.
The description that is obtained of this moveout phenomenon is asymtotically static, which is to say, as the buried LVT approaches the surface, the description is identical to surface consistent statics. Thus, conventional statics' modelling is a special case of STAR corrections. Furthermore, like statics, the fundamental information required is the vertical transmission time through the anomaly. However, this simplified theory makes no attempt to account for the effects of wave front "healing" which will modify predictions based on ray considerations only. This aspect is investigated using wave equation modelling.
The effect on the reflection time curve of a reflector, due to the presence of buried stream channels, shallow gas "pockets" and erosional (or dissolved) surfaces with low velocity fill, can be modelled as a low velocity thin layer (LVT). The distortion of RMS velocity measurements and of the structure picture represented by the stack section, due to such buried static anomalies, could be substantially reduced.
Static And Dynamic Failure Of Rock Under Chisel Loads
Authors: Singh Madan M. , Johnson Arvid M. 
Published: December 2007

Abstract
The mechanism of failure under a drill bit is still improperly understood in spite of several investigations of the subject. Generally, the cratering process under static loading conditions is considered to be similar to that achieved dynamically by impact. But this paper attempts to indicate that, although the sequence of fracturing in the two cases appear to be indentical, at least some dissimilarities exist. For example, the width-to-depth ratios of the craters vary to some extent, and the amount of energy consumed per unit of volume of craters is unequal for the two different loading conditions.
A complex brittle-elastic-viscous-plastic rheological model could probably explain in detail the phenomena of failure beneath a drill bit for the types of rocks tested. The types of fracturing seem to be similar under the two loading conditions, so that a model with a viscosity term may be assumed to explain effects of differences in loading rates. Further, the generation of extension fractures may be explained by a brittle-elastic model, and the de formation of the intensely fractures zone around the tip of the wedge-shaped bits might be described by a plastic model.
Extension fractures formed beneath the bit are important to a study of volume-energy relationships, because the fractures provide new free surfaces into which chips can be developed.
Offshore Loading of Oil and Gas — How Increased Availability can be Achieved
Authors: Misund A , Tveit O 
Published: December 2007

Abstract
The paper will first give a brief summary on the technological developments of offshore loading systems and a prediction of future trends and challenges.
Based on previous studies of several different design concepts, the paper will deal with the methods applied in the analysis and factors contributing to the unavailability of offshore loading systems.
The following categories are discussed: –Environmental factors limiting the availability of the plant.–Structural failures, non-scheduled repairs and inspection.–Process system and operational failures and the associated repiar, causing off hire.
The result of the availability analysis will be identification of components and conditions contributing to availability.
It will be shown how the knowledge in turn can be utilized in formulating redundancy and more specific design related criteria and guiding inspection and maintenance during operation. The use of the analysis in evaluating relative value of different design solutions will be discussed.
The last part of the paper will give specific guidance and recommendation on design, fabrication and operation of offshore loading systems based on many years of involvement in ail phases of offshore loading systems, i.e. –research–conceptual evaluation–certification–in-service inspection–rule and guidance development.
Transmission, Storage And Export Of Product From The Arun Field
Authors: Soeryanto Joko 
Published: December 2007

Abstract
Arun LNG plant is the second Indonesian LNG plant. It began production of LNG in August 1978. The plant site is located in the North Coast of Sumatra, is owned by PERTAMINA. Plant feed is supplied from the Arun gas condensate field located approximately 30 kms from the plant.
The overall complex is designed to produce LNG equivalent to 18 MM NM3 per day of gas, and 12,000 M3 per day of stabilized condensate.
Field facilities produce and separate gas and condensate for delivery through separate pipelines to the LNG plant. At the plant, condensate is stablized and stored in four 78,705 M3 floating roof tanks and subsequently shipped in conventional tankers, moored offshore.
The gas is treated, dehydrated and liquefied. Gas treating is accomplished by the Benfieid Hi-Pure process. Lique-faction is accomplished using the propane pre-cooled multi-component refrigerant process.
Refrigerant components required for the liquefaction process are produced from two fractionation trains.
Gas is processed by three parallel, identical, treating, dehydration, liquefaction trains each designed to produced about 10,700 cubic meter per day of LNG in storage. LNG is stored in three 127,200 cubic meter storage tanks. From the tanks, the LNG is pumped to the harbour area for loading into LNG tankers.
The overall complex includes the plant and harbour operations plus a complete infrastructure of housing and utilities systems to support 5000 people.
Current plans inlude the expansion of the plant by adding two liquefaction trains.
These are scheduled to start-up in 1984.
Malacca Strait Wrench Fault Controlled Lalang And Mengkapan Oil Fields
Authors: Crostella Angelo 
Published: December 2007

Abstract
The Lalang and Mengkapan oil fields are located within the Malacca Strait production sharing contract area, Indonesia, some one hundred and eighty kilometres west of Singapore.
Exploration of the 2.9 million acre area commenced in 1970, but the Lalang oil field was not discovered until 1980, following extensive seismic surveys and the drilling of eight dry holes. The discovery of the Mengkapan oil field followed in 1981.
In both fields the oil is reservoired within sands of the Sihapas Group of Early Miocene age. Geochemical data indicate that the shales interbedded within the Sihapas Group are the source rocks for the oil. Notwithstanding their young Late Tertiary age, these source rocks are mature for oil generation at a depth of burial of approximately 3,000 feet, due to the high regional geothermal gradient.
The trapping mechanism in both fields is controlled by the same regional north trending left lateral wrench fault. The Lalang accumulation occurs in an asymmetric anticlinal fold, bisected by the controlling wrench fault, and showing continuous growth since at least the Early Miocene. Both sections of the Lalang field have been tested; the oil/water contact is slightly shallower in the upthrown section. This appears to be a characteristic feature of the basin. The net oil pay penetrated by the Lalang — 2 discovery well on the western section of the structure is 153 feet and by the Lalang — 3 well on the eastern one is 316 feet. Cumulative flow rates obtained by drill stem testing were 7,092 bopd in the No. 2 well and 10353 bopd in the No. 3 well.
The Mengkapan accumulation is contained in an elongated upthrown half anticline to the east of and paralleling the controlling wrench fault. Four discrete oil pools totalling 234 ft. of net pay were penetrated in the Mengkapan No. 1 discovery well. Cumulative flow rate from 6 drill stem tests was 12,017 bopd.
The discovery of the Lalang and Mengkapan oil fields opens a challenging new horizon to oil explorers, as the prolific Tertiary Central Sumatra Basin has now been proved to extend offshore from the island of Sumatra into the Malacca Strait.
Maximization Of Footage Drilled Before Drill Steels Fail In Fatigue
Authors: Paul B. , Fu C.C. 
Published: December 2007

Abstract
Experiments indicate that the fatigue limit of various drill steels becomes vanishingly small in the presence of water and other corrosive liquids. Therefore one must generally expect fatigue failures of drill steels in a great many field operations. However, it is theoretically possible to so choose the hammer impact speed of a percussion drill in order to maximize the total length of hole drilled before failure occurs. In this paper the existence of an optimum speed is demonstrated and it is shown to be comparable to presently used piston speeds. The influence on drilling speed and hole length of a number of other pertinent design features, such as bit geometry, hammer geometry, and steel properties is also established.
An Iterative Matrix Solution Technique for Steamflood Simulation
Authors: Wallis John R. , Coats Keith H. , Vohra Ibrahim R. 
Published: December 2007

ABSTRACT
Iterative techniques, such as line successive overrelaxation (LSOR), have generally proven to be ineffective in solving linear systems of equations arising in thermal reservoir simulators. This is partly due to the occurrence of negative effective compressibilities or transmissibilities which can occur when cold fluids move into blocks having steam saturations. This paper describes an effective iterative method for solving steamflood equations using partial elimination followed by block successive overrelaxation on the reduced matrix. This scheme has been implemented in a steamflood model allowing any number Nc of components. The model's implicit formulation requires the solution of a linear system of equations in which each grid block has Nc + 1 unknowns.
A cyclic steam stimulation process provides a severe test for the iterative technique. During the production portion of the cycle, cold fluids can flow into the steam zone causing the negative compressibility/transmissibility relationship mentioned above. The flow of cold fluids into a steam block is a physically real, dominant feature of both cyclic stimulation and steam-bank flooding. This paper presents data and model results for two such test problems, including comparisons of slice (planar) SOR, direct solution using D-4 ordering and the proposed method. These comparisons indicate that for three-dimensional problems involving a large number of blocks and/or components, this iterative approach can reduce storage by factors of two to four and CPU time by factors of three or more. In comparison with standard SOR techniques, the proposed method has proven to be significantly more reliable for steamflood problems.
A Three-Phase Model For Fractured Reservoirs Presenting Fluid Segregation
Authors: de Swaan Abraham 
Published: December 2007

ABSTRACT
A model has been developed to describe the behavior of naturally fractured reservoirs with black oil in which high transmissibility in the fractures and low oil production rates allow the gravitational segregation of the gas, oil and water phases. The influxes of these fluids from the matrix rock to the fractures are described by functions dependent on the properties of the reservoir fluids and the matrix rock blocks. These properties are measurable by laboratory tests on cores and formation studies in the reservoir. This approach contrasts with a common trend in fractured reservoir simulation favoring the use of parameters to account for the matrix-fracture interaction; these parameters cannot be explicitly linked to the reservoir characteristics.
The presented formulation results in a system of three simultaneous integro-differential equations where the dependent variables are: the dephts of the gas-oil and water-oil contacts, and the pressure at the datum. Observed and calculated variables, obtained applying the model, are in good agreement throughout the forty-five years long production history of an actual reservoir that includes a period with null production, while all the wells were closed, that resulted in an unusual fluctuation of the variables.
The Development and Testing of a Sequential Semi-Implicit Four Component Reservoir Simulator
Authors: Watkins Robert William 
Published: December 2007

ABSTRACT
This paper describes the application of the sequential, semi-implicit saturation formulation to a four-component, mixing parameter-type miscible flood reservoir simulator. The semi-implicit saturation formulation has greater numerical stability than an IMPES formulation.
Furthermore, a comparison was made between results obtained with this simulator and a fully compositional simulator. When consistent fluid descriptions were used, results predicted by the two simulators for primary production, waterflooding, and miscible gas drive were in excellent agreement. Under conditions where significant amounts of free hydrocarbon gas existed, the mixing parameter model predicted more optimistic but qualitatively similar reservoir performance.
A Simulation Study of Detergent Flooding in a Vertical Cross Section
Authors: Cruz Dominguez-V Guillermo , Dougherty Elmer L. , Handy Lyman L. 
Published: December 2007

ABSTRACT
A two-dimensional, fully implicit, numerical model for simulating detergent flooding is presented. The model considers the typically observed relation between detergent concentration in the water phase and interfacial tension, with this relation exhibiting a strong minimum at the critical micelle concentration. Interfacial tension and relative permeability are handled via a relationship developed from recent laboratory studies at the University of Southern California. The results obtained to predict effect of various parameters on oil recovery, from a system already waterflooded are presented. Parameters considered include location of injection interval, slug size, surfactant concentration, oil viscosity and injection rate.
Development of a Complicated Fault-Block Oil Field by Waterflooding
Authors: Chengguo Ma , Shirong Shuai , Yu Jin 
Published: December 2007

ABSTRACT
The oil field is characterised by multiplicity of faults that cut the field into small blocks. Development units are divided into three classes according to the amount of natural energy. Insufficiency of natural energy is the main feature of development of the field which dictates the application of waterfloding in time to replenish energy. The point is emphasized that different types of units are to be differently treated in the maintenance of energy by flooding in respect to the level of pressure to be maintained and the appropriate time for the start of flood. A comparative study of different types of flooding is also made.
Reducing the Drag Force of the Multiple Phases Flow in Gathering Lines by Injecting Demulsifiers at Wellhead
Authors: JianZhong Huang 
Published: December 2007

ABSTRACT
This paper describes the laboratory experiments on two phase oil-water emulsion. A technique of continuous injection of chemicals at the wellhead to break the emulsion and to reduce tne resistance in the \ill\ is suggested.
This method can be used at tne water cut production wells without heating, thus reducing energy consumption and production costs.
The Effects of Various Parameters on the Thermal Stresses in the Pipe Bends of Underground Pipelines
Authors: QiangKang Cai , YingMin Lü 
Published: December 2007

ABSTRACT
The effects of various parameters on the thermal stresses in the pipe bends of underground pipelines have been investgated by the finite element method. According to the results of calculation, many graphs have been drawn to show these effects. It has been found that among the various parameters, the ratio of the radius of curvature of the bend to the outside diameter of the bend, the angle of the bend and the lateral soil pressure acting on the pipeline are the most important ones.
Mechanism of Tertiary Oil Recovery by Aqueous Chemical Flooding
Authors: Kamath Krishna I. , Zammerilli Anthony M. , Comberiati Joseph R. , Taylor Billy D. , Slagle Franklin D. 
Published: December 2007

ABSTRACT
The tertiary recovery of oil by chemical flooding is an admittedly complex process involving both micro and macroemulsions. The work reported here suggests from fundamental considerations of theory, operation and economics that in situ emulsification of the immobile residual oil (and mobile secondary oil) in the petroleum reservoir and its transport as such to the producing well is feasible and has many advantages over miscible processes. These include freedom from mobility control and ultralow interfacial tensions that call for substantial chemical outlays. Arguments are presented in support of this view with tertiary oil recovery data obtained from Berea core floods using cosurfactant-free aqueous solutions of two hydrocarbon sulfonates differing substantially in their solubility in water. A brief discussion of pertinent EOR methods is given, emphasizing the occasionally obscured but significant distinction, from an EOR-perspective, that exists between the mobile (secondary), and immobile (tertiary) components of the reservoir oil targetted by these processes.