bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model for Locating Fluids' Contracts in Petroleum Reservoirs
Authors: Udegbunam E. O. , Numbere D. T. 
Published: December 2007

ABSTRACT
Direct determination of the gas-water contact (GWC) or the oil-water contact (OWC) in new wells from geophysical logs, core analysis data and/or whole core inspection is often difficult. Rapidly changing reservoir quality in the interval of interest or gradually changing saturation profiles in the vicinity of the contact can make the determination of the GWC or OWC difficult. This paper presents a model for the accurate placement of the GWC or OWC. The input data are water saturations at various well depths as interpreted from induction logs and the average residual oil saturation. When available, permeability and porosity values from core analysis may improve the result.
Using a power-law equation or a Langmuir isotherm-type equation to represent the capillary pressure-saturation relationship, the GWC or OWC is expressed as a function of water saturation and well depth. A nonlinear optimization technique is then used to determine the GWC or OWC.
The applicability of this model is demonstrated with a field example. The calculated OWC values from all variations of the model fall within 4 feet of the actual OWC value. This model can only be applied in an oil or gas well where an equilibrium capillary curve and a hydrocarbon-water contact occur.
Well Site Digitizing Equipment For Mineral Exploration
Authors: Gearhart Marvin , Hallenburg James K. , Foote Robert S. 
Published: December 2007

Abstract
A large gap exists between the type of equipment in general field use for mineral exploration and the latest state of the art type digitizing equipment. Economic considerations and technical capability of the average logging operator are the two main reasons for this gap.
A new generation of digitizing equipment used for digitizing depth and gamma count rate in uranium exploration holes presents the data on printed tape. This is one of the simplest systems available but still requires key punching before the log data is computer compatible. Such systems are used primarily in the development drilling and economic evaluation of ore bodies. Exploratory logging units are seldom equipped with even this simple type of digitizing equipment since the rate of uranium discoveries is quite low and actual usage would be minimal if on all logging units.
Highly sophisticated digitizing systems of a laboratory type are being field tested for exploratory logging units engaged in basic mineral prospecting. Such systems analyze and process well log data on-site and identify basic elements. The evaluation of californium-252 as a neutron source for mineral exploration by neutron activation analysis is assisted by the use of such a computer system.
Introduction
Digitizing of well logs at the well site seems to be lagging behind the previous expectations of people in the industry. There are specific areas where well site digitizing has been widely accepted, such as in uranium logging. Digital techniques and automatic data processing systems offer the only practical solution for handling large volumes of data accumulated. In the evaluation of uranium deposits by the use of well logs, the logs are accumulated rapidly and final results from the processed data must be obtained quickly. Therefore, beginning with simple digital tape printouts and in some cases advancing to punched tapes, printouts and in some cases advancing to punched tapes, uranium logging field units are currently producing most of their data in both analog and digitized form. Field examples are used to demonstrate typical systems in current use. Such systems are relatively inexpensive and require a minimum of skill to operate.
Highly sophisticated well site digitizing systems are being used for research purposes and one such system is described.
INDUSTRY PRACTICES
Evaluation of the economics involved in all phases of the exploration and development of a mineral deposit have always been essential to the planning of a successful venture.
Well Data Files And The Computer Exploration Tools For The 70's
Authors: Stark Philip H. , Forgotson James M. 
Published: December 2007

The purpose of this paper is to illustrate how the computer can be used for processing well data files to provide information that is not only useful for exploration, but essential for economically efficient exploration where large amounts of data from previous drilling are available.
The Industry has made a concerted effort to manage the large volumes of data required to obtain maximum efficiency in the exploration for petroleum and the production of known petroleum and the production of known reserves.
With respect to computer handling of data, the past decade was devoted primarily to accumulating information primarily to accumulating information and building large files of well data and production data within the industry, and special geological or other technical data files within certain companies. The petroleum industry is the only segment of the mineral industry that has a comprehensive data base available in computer processable form. During the decade of the 70's we will see the benefits of these costly investments.
Figure 1 shows the areas of well data file coverage within the United States. Boundaries of each of the nine systems conform generally to the major geological provinces. All producing areas in the provinces. All producing areas in the United States except California and Alaska are covered. Similar systems are operated by the provincial governments and a commercial organization in Western Canada. Approximately 2,200,000 wells have been drilled in the search for oil and gas within the United States and Canada, of these about 1,000,000 have records of sufficient quality to include in a computer-based data system. Petroleum Information currently has approximately 700,000 wells in computer processable data files.
Data are obtained from a variety of sources: Directly from the well site, from state sources, and by field men or contact men who obtain data from the operators of the wells.
How to Organise Mud Logging Data For Modelling Rate of Penetration
Authors: Xu Hong , Fear Martyn , Whelehan Oliver , Ford John , Jensen Jerry 
Published: December 2007

ABSTRACT
ROP (Rate of Penetration) modelling can provide a quantitative tool to reduce drilling costs by means of bit selection and determining the optimal combination of mechanical and hydraulic operating parameters. It is recognised that it would be desirable to model ROP using mud logging and electric wireline logging data because such data closely represent the drilling conditions and formation properties respectively. However, this approach has long been diminished by the apparent poor quality of the data available.
This paper examines the nature of logging data and describes the relationships between ROP and its related variables. We propose an approach to improving ROP modelling using field data. As a result, a number of empirical ROP models have been developed using routinely available mud and wireline logging data. The models are shown to be physically valid under a wide range of conditions. An appreciation of the ranges of conditions under which the model will apply is a critical consideration given the varying contribution of factors affecting ROP under different drilling conditions. The validity and robustness of the new approach are demonstrated by applying it to the logging data from three Poly-crystalline diamond compact (PDC) bit runs in the North Sea area. The method holds the potential to be fully automated for routine application.
The Application of A New Polymer Mud to Horizontal Drilling in the Dagang Oilfield
Authors: Yan Jienian , Jiang Guancheng , Zong Ruiguo 
Published: December 2007

ABSTRACT
A new kind of polymer muds, which is generally referred to as the amphionic polymer mud, has been applied to the two horizontal well driling for the first time in the Dagang Oilfield, located in east China. In this mud system, two amphionic polymers are usually used as the main additives, the one with high molecular weight is an inhibitive encapsuler and filtration control agent, and the other one with low molecular weight is a deflocculant. The amphionic polymer, just as its name, is defined as the polymer that both organic cations and anions simultaneously exist in their molecular chains.
The design criteria, formulations and properties of this mud system are discussed. As a case history, the field performance of this new polymer mud in the different sections of the second well (by name Guan H-l, a medium-radius horizontal well) is also given.
It was shown from the laboratory and field tests that the amphionic polymer mud not only has all the advantages of the polymer muds commonly used, but is able to overcome the disadvantages of those muds, indicated by its highly inhibitive character while maintaining excellent mud performances. For this reason, the major drilling problems for horizontal wells in the Dagang Oilfield, such as hole cleaning, wellbore stability, lubricity, lost circulation and formation damage, which were hardly solved by the use of other water-based muds, could be solved successfully by the use of the amphionic polymer mud at much lower cost than the oil-based mud.
New Tool Designs for High Rate Gravel Pack Operations
Authors: Ross Colby M. 
Published: December 2007

Abstract
A universally accepted practice in the oilfield has been fracturing of the wellbore to improve hydrocarbon recovery. Fracturing procedures reduce skin by breaking through or bypassing near wellbore damage that inhibits production. In loosely consolidated formations, a propped fracture can reduce fluid velocity in the near wellbore region, which subsequently reduces fines migration that can plug the wellbore. Fracturing also provides highly conductive paths for gas and oil production.
Gravel packing is another operation that is often needed during a well's productive cycle. When a highly-conductive fracture is created before a gravel packing operation is run, it has been found that well productivity increases. Performing the operations separately, however, diminishes the productivity gains because of formation damage that can occur between completion operations.
A method of gravel packing that includes a tip-screen-out-design fracturing procedure, performed with the gravel pack packer, screen, and blank in the hole, was proposed to allow the procedures to be performed simultaneously. This paper will describe the various types of gravel packing tools that are currently in use, their specific application, and a new series of gravel packing tools that was developed to resolve the difficulties that arose when the operations of fracturing and gravel packing were combined. Also discussed is the need that arose for tools that could sustain high flow rates in small casing diameters.
Test results will be used to provide acceptable flow rates for different bore sizes.
Sound Reservoir and Production Management will Enable Fifty-Eight Percent Oil Recovery in Colombia's Cano Limon Field
Authors: Ellison R. L. , Ahumada R. 
Published: December 2007

Abstract
The Caño Limón Field, discovered in 1983, is the giant oil field that made Colombia self-sufficient in oil. The field contains over a billion barrels of recoverable oil, and as of publication date, has produced over fifty percent of its reserves. The current production rate is 215,000 BOPD. Sound reservoir and production management has resulted in an expected ultimate oil recovery of about 58 percent of the Oil-in-Place. The field has a current watercut of 80%, thus, the operator is managing the high disposal of large volumes of produced fresh water (over a million barrels per day) with minimum impact on the environment. This has been accomplished by treating and disposing the produced water with compliance of strict environmental guidelines.
High recovery factors have been achieved by the implementation of technologies such as those listed below:
Reservoir management techniques used to define new well locations and strategically select completion and recompletion intervals by: a) making extensive use of a 3-D simulation model, and b) implementing a well defined program of reservoir monitoring using production logs, single well pressure tests and multiwell interference tests.
Experience with state of the art electrical submersible pumps (ESPs) and variable speed drives (VSDs) in lifting large fluid volumes, up to 22000 BFPD per well, with associated sand production ranging from 0 to 200 ppm. This has enabled high oil production rates to be maintained, and oil recovery to be maximized in spite of the high watercuts associated with this very active water drive field. ESP completions with Y-tools are strategically placed to provide for the ability to perform reservoir monitoring surveys.
Automated and continuous well production measurement techniques (rates and watercuts) are used to monitor individual well performance, allowing for the implementation of corrective actions in a timely manner.
Treatment and disposal of the large amount of produced water in compliance with strict environmental guidelines.
The field is located on the eastern edge of the Llanos (Plains) of Colombia, in an ecological area that can be described as flood plains. This area is normally flooded during the rainy season from June through October. Measures are taken to restore and maintain the natural environment of the area.
Gathering System Optimization in a Gas Field with Commingled Flowlines
Authors: Soetedja Vincensius , Harun Amrin F. 
Published: December 2007

Abstract
Badak Field, located in East Kalimantan, Indonesia, is a giant onshore gas field with 181 wells and total gas deliverability of 1.3 billion standard cubic feet (BSCF) per day. In many cases, gas from more than one well is commingled in the same flowline. This study concludes that commingling flowlines has been extremely cost effective over the life of the field. However, good initial design is required to anticipate future reservoir depletion and recompletions in order to achieve the best economic efficiency.
Correct Production Rates Eliminate Sand Production in Directional Wells
Authors: Budiningsih Y. , Hareland G. , Boonyapaluk P. , Guo B. 
Published: December 2007

Abstract
This paper shows how rock strength analysis can be utilized in preventing wellbore collapse and sand control problems during production of directional wells. From this study it is seen that selecting the correct production rate can avoid wellbore collapse which cause sand production. When the production rate is increased the reservoir drawdown near the wellbore cause an increase in the effective wellbore wall rock stresses. Using the von Mises rock failure criteria for wellbore stability analysis, the maximum production rate without formation collapse and sand production can be estimated. The parameters that effect the rock stresses at the borehole wall are the in-situ stresses, wellbore inclination and direction, and fluid pressure in the rock which is a function of the production rate. If the decrease in the near wellbore fluid pressure due to high production rate causes the effective stresses to exceed the failure criteria the wellbore will collapse to a certain new diameter. After the new diameter is estimated the volume of produced sand is calculated. The study concludes that possible sand production should be carefully analyzed in all directional wells. The wellbore sand production is a much more severe problem in directional wells and might limit the production rate. The maximum production rates with no sand production can be obtained using the approach in this paper.
Hidden Oil Leg : Case Study of the Lower D1 Miocene Sandstone, Dulang Field, Offshore Peninsular Malaysia
Authors: Solomon G. J. , Chandramohan S. , Karra S. , Sonrexa Kartikay 
Published: December 2007

Abstract
The Dulang Field is located offshore east coast of Peninsular Malaysia in water depths of approximately 75 m. The field, discovered in 1981, is about 24 km by 3.5 km. After drilling 14 exploration/appraisal wells by both Carigali and its partner Esso Production Malaysia Inc., the central part of the field was developed as a unitized area in November 1990. Three 32-slot platforms have been installed in the unitized area, and development drilling is ongoing. Production commenced in March 1991 and is currently maintained at approximately 50,000 BOPD. The estimated OIIP (oil-initially-in-place) for the unitized area is in the order of 700 million barrels.
There are 19 reservoir sands in Groups D and E which are of Middle-Late Miocene age. During the exploration/appraisal phase, oil and gas were encountered in the Group E and only gas in the Lower D1 reservoirs. Wireline formation pressure test data taken in the Lower D1 reservoir in these wells plotted along a common trend with a gradient of 0.06 psi/ft. The lowermost gas pressure point was only 6 m above the normal hydrostatic gradient.
It was therefore concluded that an oil column, even if present, would be thin. At the time, it was understandable that the gas pressures plotted along the same trend because the hydrocarbon column of the Lower Dl reservoir was large and extended beyond the limits of the major faults, suggesting a common pool. However, during the development drilling phase, it was discovered that the Lower D1 sandstone was a major oil reservoir, with estimated oil-in-place of about 100 million barrels. Oil columns of 75 m and 40 m have been proven up in the northern and southern flanks of the field, respectively, in the Lower Dl. In addition, development plans were flexible enough to be able to effectively exploit the discovery.
The well and formation pressure test data suggest that the Lower Dl has a common pressure system in the gas cap over the central part of the field but different systems in the oil columns. Faulting is suspected to have provided both conduit and seal at different times to accommodate this phenomenon.
The Significance of Large Variations in Oil Properties of the Dai Hung Field, Vietnam
Authors: Behrenbruch Peter , Du Pham Quang 
Published: December 2007

ABSTRACT
The Dai Hung Oil field, offshore Vietnam, is comprised of a complex subsurface structure containing stacked reservoir sequences typically found in many other Southeast Asian fields. Combined with areal fault compartmentalisation, this situation has led to the observed, large variations in oil properties. Furthermore, the depositional environment in terms of burial history has created a unique overpressure situation which also had an affect, particularly on the crude saturation conditions of individual reservoirs.
For commercial and technical reasons, this situation required a detailed analysis, both in terms of variation in crude assay and live oil properties. For whole crude properties: gravity, K factor, wax content and pour point – graphs were drawn up using a large data base of worldwide crudes against which the Dai Hung data could be validated. In case of PVT properties (bubble point and formation volume factor) existing industry correlations were examined.
It could be concluded that the sweet, medium gravity and moderately waxy Dai Hung crude has whole crude properties which are comparable to other, similar crudes.
The general framework of crude properties established is suitable to type other crudes, even if limited information is available.
Of the existing PVT correlations tested1-5, it was found that Standing's1 correlation for the oil formation volume factor and the Kartoatmodjo-Schmidt5 correlation for the bubble point fitted the Dai Hung crude data the best. For the lower shrinkage Dai Hung crudes the Malaysian oil formation volume factor correlation by Omar-Todd4 gave the best data fit.
Optimisation of a Large Integrated Area Development of Gas Fields Offshore Sarawak, Malaysia
Authors: Inyang Samuel Edward , Tak Andrew Ngu Hew , Costello Gerry 
Published: December 2007

ABSTRACT
Optimisations of field development plans are routine in the industry. The size, schedule and nature of the upstream gas supply project to the second Malaysia LNG (MLNG Qua) plant in Bintulu, Sarawak made the need for extensive optimisations critical to realising a robust and cost effective development scheme, and makes the work of more general interest. The project comprises the upstream development of 11 offshore fields for gas supply to MLNG Dua plant at an initial plateau production of 7.8 million tonnes per year of LNG. The gas fields span a large geographical area in medium water depths (up to 440 ft), and contain gas reserves of a distinctly variable gas quality.
This paper describes the project optimisation efforts aimed to ensure an upstream gas supply system effectiveness of over 99% throughout the project life while maintaining high safety and environmental standards and also achieving an economic development in an era of low hydrocarbon prices. Fifty percent of the first of the three phases of this gas supply project has already been completed and the first gas from these fields is scheduled to be available by the end of 1995.
Practical Methods to Forecast Production Performance of Horizontal Wells
Authors: Permadi P. 
Published: December 2007

ABSTRACT
Hundreds of horizontal wells have been drilled and completed successfully in many oil producing countries. When properly utilized, horizontal wells produce more oil at lower cost. To support its economic evaluation, production prediction models are needed before the implementation.
This paper presents two analytical methods for predicting performance of a horizontal well. One method uses a steady-state inflow equation to estimate breakthrough time for water. The second method proposed, which has been derived from a pseudosteady-state inflow and material balance equations, is suggested to forecast oil production versus producing time. The former method should be used for a horizontal well producing oil from a bottom water drive reservoir, while the latter should be applied to a horizontal well producing from a depletion drive reservoir.
Field examples are given to show that the proposed methods work well. The presented correlations may help field engineers in designing or evaluating their planned horizontal wells before a sophisticated prediction tool available on hand.
Experience in the use of QRA to Prioritise Safety improvements on Offshore Platforms
Authors: Hanson R J , Lewis K J , Walters K 
Published: December 2007

ABSTRACT
The objective of this paper is to share Brunei Shell Petroleum's (BSP) experience in using QRA to help understand risks in offshore operations and to identify and prioritise ways to improve.
This paper presents an overview of the results of the QRA studies using the work for one installation as an example and describes how potential improvements were identified and evaluated. It shows how this objective approach can help effective management decision making to improve safety and reduce business risk. Future goals and challenges and the interaction of this work with the Company's long term strategic planning are discussed briefly.
A New Contracting Strategy Improves Well Construction Quality and Efficiency
Authors: Varco M. R. , Boyle John , Richardson Mike , Oag Alistair 
Published: December 2007

ABSTRACT
In today's mature North Sea environment every effort must be made to increase efficiencies in order to increase the return on investment of both operators and contractors.
A new contracting strategy has been introduced to improve drilling efficiency, while ensuring all well quality measures are met. As a result of this strategy, the BP Bruce field is one of BP's most effective, fully integrated North Sea drilling operations.
This paper describes the steps taken to successfully implement this strategy and the benefits that have resulted.