First Retrievable Directional Casing While Drilling (DCwD) Application in Peruvian Fields Generates Time Reduction and Improves Drilling Performance Preventing Potential Non-Planned Downtime

Abstract

Drilling Operations in Peruvian Jungle requires a complex logistical preparation similar to an offshore project. This high logistic cost that is necessary to drill in this area means a big investment and strongly impacts the daily drilling cost. To minimize potential non productive time (NPT), potential problems that were identified in offset wells (borehole instability, gumbo shales, stuck pipe, etc.), and to improve the drilling performance, Perenco Peru Limited decided to use Directional Casing while Drilling (DCwD) technology in their Block 67 campaign wells. Two wells (Piraña-4D and Dorado-2D) were drilled with this technology obtaining success and achieving the operator's targets. The objectives for the Casing Drilling operations on the Block 67 wells were: Prove feasibility of both vertical and directional casing drilling technologies Save time upon the whole section by simultaneously Drilling and casing-off problematic formations Demonstrate efficiency of the technology to reduce risks associated with conventional drilling that could easily result in losing the well and further unplanned sidetracks Prove adaptability of the technology to different well conditions (mainly variance on well trajectory) Evaluate the economical viability of the technique (cost & time savings) This paper describes these experiences in terms of planning, preparation, execution and evaluation of results including the lessons learnt generated during the process.

Computational Modeling of Drilling Fluids Dynamics in Casing Drilling

“…Several examples from applications around the world include Canadian arctic permafrost by Vrielink et al (2008), Lobo field in south Texas by Fontenot (2003), in Brazil by Placido et al (2005 and, Mississippi Canyon by Rosenberg and Gala (2012), in Peruvian Jungle by Beaumont et al (2010), in Saudi Arabia by Chima et al (2012), in Gabon by Askew et al (2011), in San Juan basin by Robinson et al (2008), and finally in Oman by Sanchez et al (2012). The theory behind the field observations has not been fully understood yet.…”

Directional Casing While Drilling (CwD) Reestablished as Viable Technology in Saudi Arabia

“…The DCwD response is not significant dissimilar than the regular approach when conventional drilling is used (Beaumont et al, 2010), but requires additional equipment for tripping out and in with a specific set of running tools (to retrieve or set a new BHA). Under this circumstance (casing string on slips and drillpipe inside with running tools), there are two different flow paths from where the well can take an influx:…”

A Review of Casing Drilling Advantages to Reduce Lost Circulation, Improve Wellbore Stability, Augment Wellbore Strengthening, and Mitigate Drilling-Induced Formation Damage

“…The Casing Drilling application was able to meet the planned objectives of drilling the shallow hole sections in a total loss scenario uneventfully", (Gallardo et al 2010). Beaumont et al (2010) reported another successful Casing Drilling application in Peruvian fields. "The main problem in this area was time-consuming gumbo events in the intermediate hole.…”

“…Severe drag and tight spots led to high risk trips out-ofhole requiring extensive back-reaming and near-lost hole events in offset wells (severe pack-offs while tripping out). Potential problems associated with hole instability, clay swelling, stuck pipe, hole cleaning, gumbo, surface equipment downtime and seepage losses were entirely mitigated with Casing Drilling application", (Beaumont et al 2010). Torsvoll et al (2010) have done a case study on the successful application of Liner Drilling technology in Norwegian Continental Shelf (NCS) where many fields have formation instability and/or depletion history.…”