This paper reviews photogrammetric error sources and their impacts on modeling and surveying for construction quantity takeoff, quality control, and site safety monitoring applications. These error sources include camera internal parameters (i.e., type, principal point, principal distance, and camera lens distortion coefficients), imaging settings (i.e., shooting distances, baselines, percentage of photo overlaps, number of overlapping photos, camera intersection angles, and angles of incidence), and processing software programs. To augment the body of knowledge on photogrammetric modeling errors, this paper further conducts experiment, which concerns characterization of the behavior of different strategies in selecting reference lines for fixing absolute scale of photogrammetric models. In construction photogrammetric surveying, it is imperative to convert the relative scale of a 3D model into absolute measurements so geometric measurements can be taken. Previous work suggests this can be done through the determination of a reference line in absolute units; however, the position and quantity of reference lines has not been investigated. This experiment attempts to tackle this issue. The result shows that one horizontal reference line in the middle of the object performed with consistent accuracy, but if a specific area on the object needs more accurate measurements, it is best to select a reference line in that area. The review and the experimental findings may help construction professionals better understand the performance of the photogrammetric surveying and apply it in their real-world projects.
Shell and Eastman Teleco have developed a Slim Hole Drilling system appropriate for hole sizes less than 6 114" in diameter. Since the project was started in 1987 the system has been used in 46 wells. Nine wells contained 4 118" hole, one down to 5382 meters. Overall progress per day no longer decreases in smaller hole sizes enabling the total well design to be downsized. Cost reduction of up to a quarter (or more in some cases) are thus possible. The smaller scale of operations reduces environmental impact. Extensions such as horizontal, high pressure I high temperature, and floating drilling are underway. Complementary evaluation and completion technology allows Oil Companies to downsize production wells, potentially reducing field (re)development costs. There remain significant opportunities for the service industry to develop complementary "Slim" rigs, equipment, and services.
During the past three years, an intensive exercise has been underway in Shell Expro to improve the drilling performance in its fields Brent, Cormorant, Dunlin and Fulmar, and on mobile rigs. Expro approached this by concentrating on its primary resources: Men, Materials and Methods. The emphasis has been on trying to improve motivation, committment and knowledge by all involved in the operation, to try out new techniques and equipment where such are identified as being potentially beneficial, and to study procedures currently in use, with the object of improving the drilling efficiency.
This paper was prepared for the Second Annual European Meeting of the Society of Petroleum Engineers of AIME, to be held in London, England, April 2–3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract Shell U.K. E and P have developed in the past two years a Fortran based computer filing past two years a Fortran based computer filing and retrieval system for use on all aspects of North Sea wells. The system, which is cheap to run, is usable by anyone with a summary knowledge of FORTRAN. Examples of the application of the system are included in the paper. Introduction It was decided to implement a well data bank following the installation of computer facilities at the Lowestoft operating base in May 1971. After some research into available data management systems, one called BUFF (Basic Update Fortran File) was chosen as being the most suitable. The data are stored on files divided according to the main disciplines: drilling operations and mechanical well data, petrophysical and evaluation data, geological petrophysical and evaluation data, geological data and reservoir engineering data. All the files are stored centrally in London but are accessible to any other location provided w a data link, such as Lowestoft, Aberdeen or The Hague in the Netherlands. Figure 1 is an orientation map. REASONS FOR INSTALLING A DATA BANK From a financial point of view a technical data bank is difficult to justify: advantages tend to be realised in terms of efficiency in the use of manpower and in ability to conduct studies which would otherwise be too time consuming. The main reasons for installing the system were to provide security of information, ease of access to the data by users geographically separated, up to date information and prevention of duplication of data by storing prevention of duplication of data by storing any item once only. Once the data base is complete, its use is mainly to enable one to scan for data across a large number of wells rather than listing information about a single well. The former is an operation ideally suited to a computer, whilst the latter can usually be done better by reference to the well-file. In any case information about the equipment in a specific well is usually needed only where the well-file originated.
In construction photogrammetric surveying, it is imperative to convert the relative scale of a 3D model into absolute measurements so geometric measurements can be taken. Previous work suggests this can be done through the determination of a reference line in absolute units, but the position and quantity of reference lines has not been investigated. This paper attempts to characterize the behavior of different strategies in selecting reference lines. Factors including relative position of the reference line, the number of reference lines, and spatial relationships of the reference lines are considered. Three infrastructure objects serve as the test beds, and experiments using various layouts of scale bars (calibrated reference lines) are conducted on each object. The surveying results are then compared with ground truth data, which allows for accuracy determination and aids in determining the best strategy in selecting reference lines for scale fixing. The results from these experiments show that one horizontal reference line in the middle of the object performed with consistent accuracy, but if a specific area on the object needs more accurate measurements it is best to select a reference line in that area. Using three reference lines is ideal from a time and accuracy improvement perspective.
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