Effectiveness of simulation to compare driller’s and engineer’s methods to control wells in highly deviated fractured basement reservoirs

Abstract

There are many problems that may occur during drilling, workover, snubbing, and coil tubing. To this extent, occurrence of a kick is considered a serious problem because making a mistake in well control may lead to a catastrophe. Particularly when gas kicks are not properly controlled which eventually can escalate into a blowout. Thus, once a gas kick is detected, it has to be circulated out safely and efficiently to the surface while maintaining bottomhole pressure constant. A quick, appropriate, and an effective response to well control is paramount in order not to end up with a surface or underground blowout. Hence, there are many methods available to kill and control the well such as Driller’s method, Engineer’s method, concurrent method, bull-heading method, reverse method, lubricate and bleed method. In this research work a multiphase flow Drillbench simulator was used to conduct a comprehensive comparison between the Driller’s and Engineer’s method to determine the most effective method to kill the well in basement reservoirs. Granitic basement reservoirs are challenging because of the severe shocks, vibrations, heterogeneity, extensive fracture network, high flow rate and unexpected over-pressurized network. Consequently, this shall require proper reaction to kill flowing wells meanwhile avoid affecting other wells within the same network. A case study showed that Engineer’s method has better results and more advantages over Driller’s method since it would require only one circulation to completely kill the well and no potential for further kicks in highly fractured formation.