First SAGD Well Placement Using Non-Stationary Definitive Dynamic Surveys Passive Magnetic Ranging and Gyro While Drilling

Abstract

Abstract Drilling Steam Assisted Gravity Drainage SAGD wells requires placing the lateral section of the producer parallel to the lateral section of the steam injector and within a predefined distance to maximize production. After one well is drilled and completed, the second well is drilled using advanced wellbore positioning techniques to keep the two laterals at specific distance in close proximity to each other. Active Magnetic Ranging is frequently used for positioning of SAGD wells, whereby an electromagnetic source, such as a solenoid is run on wireline in the first well that has been drilled and distance and direction measurements are made using the MWD tool while drilling in the second well. This increases the complexity of the operation as there is requirement to convey the source tool on wireline in a horizontal well and solutions for doing this, such as a tractor or coiled tubing, add considerable expense. Passive Magnetic Ranging PMR is a common technique to estimate the distance and direction between the two wells while drilling the second well, without any requirement to run wireline tools in the offset wellbore. However, this technique requires taking at least 10 stationary surveys every stand if not more. This conventional practice leads to significant additional rig time and often increases directional drilling complexity from hole washouts to stuck pipe events. Additionally, as the wells are drilling into each other from opposite directions, both wells have high lateral and vertical uncertainty. The close proximity of both wells and the resultant external magnetic interference makes surveying an additional challenge to the BHA design and well integrity. This is the first worldwide application of drilling SAGD twin wells utilizing Definitive Dynamic Surveys DDS to save two hours per stand by eliminating all the rig times taking stationary surveys every stand for PMR as well as eliminating all the risk to the drilling operation due to the prolonged time of having the drill string stationary. In addition, it is the first time to run a solid-state Gyroscopic Measurement While Drilling GMWD tool to measure the accurate wellbore position of the drilling well. This had significantly reduced the uncertainty of the estimated distance and direction between the two twinned wells.