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.

To better understand their reservoir in a highly deviated offshore well, the operator required advanced measurements in an appraisal well over and above those normally recorded with basic LWD measurements. The data required to better characterize the reservoir were electrical image logs, dipole shear sonic imaging, high-resolution magnetic resonance measurements, and formation pressure tests as well as pressure/volume/temperature (PVT) fluid samples, all to be collected in oil-base mud. The Operator and Service Company were looking for efficient alternatives to a pipe-conveyed logging operation.After a thorough study of well details, modelling of required tractor force, and close collaboration between the operational teams of both the operator and service company, it was determined that a conveyance system including the latest generation all-terrain tractor and high-strength cable would be suitable for this operation. Compared to running on drillpipe, tractor conveyance offered benefits for this operation in terms of rig time, flexibility, and safety. The 50-m and 4,513 lbm fluid sampling toolstring used for the operation included six pairs of tractor drives, all required logging equipment, and an electronically controlled weakpoint deployed with an 18,000 lbf high-tension conveyance package.Petrophysical measurements as well as downhole formation testing and sampling were all achieved successfully using the all-terrain tractor conveyance in four logging runs, with a total tractored distance of 6,800 m in a formation with unconfined compressive strength ranging from below 5,000 psi to as low as 600 psi. The data and samples were acquired in five logging runs across the entire reservoir interval with a maximum tension of 10,500 lbf. The total operational time of 70 hr represented a time saving of approximately 72 hr compared to a pipe-conveyed operation with the same logging equipment in this setting. Successful deployment of this tractor technology offers alternatives to operators in the region for formation evaluation.