The Traveling-Cylinder Diagram: A Practical tool for Collision Avoidance
- J.L. Thorogood (BP Exploration Co. Ltd.) | S.J. Sawaryn (BP Exploration Co. Ltd.)
- Document ID
- Society of Petroleum Engineers
- SPE Drilling Engineering
- Publication Date
- March 1991
- Document Type
- Journal Paper
- 31 - 36
- 1991. Society of Petroleum Engineers
- 4.3.4 Scale, 1.6 Drilling Operations, 1.6.6 Directional Drilling, 1.6.1 Drilling Operation Management, 4.1.5 Processing Equipment, 7.2.1 Risk, Uncertainty and Risk Assessment, 6.1 HSSE & Social Responsibility Management, 1.10.1 Drill string components and drilling tools (tubulars, jars, subs, stabilisers, reamers, etc), 1.12.6 Drilling Data Management and Standards, 5.5.2 Core Analysis, 1.1.3 Trajectory design, 1.9.4 Survey Tools, 1.6.3 Drilling Optimisation, 1.1 Well Planning, 4.1.2 Separation and Treating
- 3 in the last 30 days
- 903 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
The "traveling-cylinder" diagram aids collision risk assessment during planning and collision avoidance during directional drilling at multiwell locations. Survey results can be plotted directly on the diagram, enabling an immediate visual risk plotted directly on the diagram, enabling an immediate visual risk assessment. This paper describes the conceptual basis of the diagram, how the diagram is used during planning and drilling, and how the information on the diagram can be interpreted.
For many years, directional wells have been drilled from pads and platforms close to each other with standard plan-view and platforms close to each other with standard plan-view and vertical-section drawings. Wellsite personnel sometimes have encountered serious problems with the visualization of true well separation, and convergence or divergence rates. In some instances, difficulty in interpreting the standard well plots apparently has contributed to subsurface collisions. An alternative way of displaying the information is needed to improve safety in this type of operation. To aid collision avoidance effectively, the chosen method must (1) represent a complex situation simply; (2) clearly present the relative positions and convergence rates of other wells with respect to the positions and convergence rates of other wells with respect to the plan under consideration; (3) show the actual position of the well plan under consideration; (3) show the actual position of the well being drilled relative to its planned course and to adjacent wells with a minimum of distortion; and (4) present complex 3D interwell tolerances on the allowable position of the borehole trajectory simply and unambiguously.
The traveling-cylinder diagram meets these requirements. The original hand-drawn version was developed by Lyons and Mecham for use at the THUMS offshore development wells. The procedures were gradually computerized over the years to increase procedures were gradually computerized over the years to increase efficiency and to reduce errors. The projection reportedly was derived from a technique used to check for physical interference in pipework in a chemical plant. Hough describes an early system for computerized collision checking used in the Southern North Sea in the early 1970's. The first computerized implementation of the diagram was devised in 1977. During the early 1980's, the volume of computer code used in directional drilling grew dramatically as directional contractors responded to a growing demand for engineering support. 6 Various algorithms were devised to check for interwell collisions, and software to produce travelingcylinder diagrams was developed by several companies.
Numerous references to the diagram exist in the literature, but little information on the basis of the method is available in the public domain. Because the underlying principles have not been public domain. Because the underlying principles have not been published, they have not been subjected to public discussion or peer published, they have not been subjected to public discussion or peer review. Consequently, the various implementations tend to reflect the desires of the end users and the assessments by individual designers of the computational difficulties involved. This paper shows how the four key requirements are implemented m the normal plane traveling-cylinder diagram, presents a computationally efficient implementation of the normal-plane version, and illustrates its practical application at the wellsite.
The normal-plane projection is used to display the intersection of wells with a plane constructed in space to be normal to the direction of the planned well at the point of interest (Fig. 1). The calculation is repeated at a number of points along the planned well. The results are superimposed on the same diagram (Fig. 2). The relative separation between the planned and adjacent wells is indicated by the locus of points obtained at successive depths.
|File Size||545 KB||Number of Pages||6|