3D Printing Used to Remedy Drilling Total Lost Circulation Events

Abstract

Lost Circulation is a well-documented drilling industry issue stemming back to when oil wells were first drilled, and today lost circulation still represents a significant challenge when drilling a well bore. Drilling a well bore using standard drilling practice uses a drilling fluid to act as a primary safety barrier, a drill bit cooling medium and a method to transport drilling cuttings from the well bore. The drilling fluid is continually circulated during drilling operation: down the drill pipe, back to surface up the annulus created between the drill pipe and well bore, drillings cuttings are then removed from the drilling fluid, and the drilling fluid then pumped back down the drill pipe. Lost circulation is where the drilling fluid pumped down the drill string no longer arrives back at surface but leaks into the formation through which the well bore is being drilled. Lost Circulation events can represent well control issues, significant drilling fluid costs, lost time in controlling and/or remedial curing operations. These issues are documented to add millions to the cost of drilling operations annually. Lost Circulation is described using several categories that relate to the rate of the loss and mechanism of the loss event, these categorized descriptions are then used to catalogue and describe the types of solutions available to cure the lost circulation. Lost Circulation severity is categorized by the volume of drilling fluid that is lost or not returned to surface. The widely accepted categories used are ‘Seepage’, ‘Partial’, ‘Severe’ and ‘Total’ Losses. Each of the four categories are defined with a fluid loss flow rate, some generally accepted definition rates are shown in Table 1 (Drilling Specialties Company, 2014).