fax 01-972-952-9435. AbstractA majority of industry operators and service companies have adopted directional drilling collision avoidance rules based on stringent controls to prevent surface collisions and consequent human and environmental damage. These rules are found to be severely restrictive for the optimal positioning of wells through deeper reservoir zones where the level of damage from collision can be contained.A new method is proposed that retains existing rules for avoidance of shallow (severe outcome) collisions and provides the option for use of risk based rules in deeper sections of wells where the outcome of a collision would not be as severe. The risk level of collision with respect to any offset well is calculated and then converted to a Risked Clearance Factor, an established standard for evaluating different levels of collision tolerance in wells.Deep intersections have several characteristics which require separate treatment from shallow intersections. They have high convergence angles which minimize the physical space and distance where a collision may occur and they have lower economic risks of a collision relative to the cost of corrective action. This method has been implemented in a field area of rapid prospect planning and development. The rules are designed to be simple and practical in order to reduce planning and drilling cycle time. A matrix of risk elements, specific to the field area is presented for different depths of collision to help to derive the level of tolerable risk. A case history is presented that shows the clear benefit of utilizing the alternate method. Resulting ActionNo action required.

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