This paper will discuss the deployment of the concentric dual diameter fixed cutter bit technology which was introduced in January 2015. The bit was deployed and tested several times in a tangent, directional application and J-shap wells in Burgan Field, South of Kuwait and achieved the fastest penetration rate in the application. The concentric dual diameter bit is composed of a smaller pilot and a larger reamer section, where the reamer section dictates the final drill size. Conventional fixed cutter bits take very little advantage of stress relieving the rock, as it only affects the borehole wall. Concentric dual diameter technology bits are able to initially drill with a leading smaller pilot section efficiently to relieve the stress of the rocks. Subsequently, the reamer section removes the stress-relieved rock with lower mechanical specific energy compared to regular fixed cutter bits, giving it the advantage to generate higher penetration rates. Another advantage of the concentric dual diameter technology bits is the stability of the bit, since two gauge sections are available to be in constant contact with the borehole while drilling. The first 12 ¼ in. concentric dual diameter technology bit in conjunction with directional 8¼ in. PDM (0.16 R/G, 7/8 lobes, 4 stages, 1.5 BH) BHA was tested in a directional application J-Shape well in Burgan Field, South of Kuwait. The bit was able to deliver improved performance by drilling the tangent section from 4345 ft to 6019 ft from Ahmadi to Burgan formation, total 1674 ft in 17 hrs with 98.4 ft/hr. The bit showed excellent steerability, building from 39 deg to 43 deg with 3 deg/100 ft max DLG severity. The section lithology consists mainly of Shale, Limestone & Sandstone. The performance capability was confirmed when the second bit run in conjunction with directional 8¼ in. PDM (0.16 R/G, 7/8 lobes, 4 stages, 1.5 BH) BHA was tested in a directional application S-Shape well in Burgan Field, South of Kuwait. The bit was able to deliver improved performance by drilling the dropping section total 940 ft from Ahmadi to Burgan formation. The bit showed excellent steerability, dropping from 15 deg to 0 deg with 3 deg/100 ft max DLG severity. The section lithology consists mainly of Shale, Limestone & Sandstone. The 12 ¼ in. concentric dual diameter was able to surpass the average rate of penetration for the same application in the Burgan Field by 56% saving the operator drilling time and making the concentric dual diameter bit design the top performing drill bit in the field.

Preventing and curing fluid losses in limestone formations is one of the most challenging loss situations to prevent and control. Loss zones are unpredictable, due to large vugular zones and extended and connected fracture structures. Often these limestone intervals are depleted reservoirs. Typically, calcium carbonate pills containing various size distributions are part of the lost circulation armory in reservoir sections. However, results are highly variable and not suitable for large-scale losses. This is distinguished for those situations with the most-severe lost circulation, where chemical sealants may be more applicable than treatments by plugging particles. The paper discusses about use of a cross-linking polymer fluid treatment that enables operators to cure lost circulation zones in many different applications, providing distinct operational and economic advantages over conventional reactive and temperature activated methods. The paper discusses the customization of the polymer fluid to have specific thickening or setting time so this loss circulation fluid can be pumped through the existing bottomhole assembly (bit nozzle size greater than 14/32nd) without losing rig time associated with tripping and mixing conventional loss circulation material treatments (LCM). The paper discusses the execution procedures and cautions to be followed to improve cross-link LCM plug placement as well as chances to arrest losses. Due to biodegradable nature of organic cross-linking polymer plugs, it was used in sensitive reservoirs with minimal effect on the formation. The cross-linked plug or pill, with time and temperature, will break back to a fluid state and may be produced back and circulated from the wellbore. The discussions in this paper will further reveal the workings and applicability of cross-link polymer fluid to lower costs for drilling fluids, cementing and casing design.

The objective of supplying real time LWD or FE information (Logging While Drilling and Formation Evaluation) should be to enable the client to make quick, accurate decisions on the formations being drilled, thus reducing and minimizing the geological uncertainty and maximizing or increasing the well bore exposure in the desired structure. During the course of drilling an 8 well Horizontal drilling program for the Kuwait Oil Company (K.O.C.) in the Burgan Field, Kuwait it became apparent that there was a need for clearer and better quality real time log information to enable the Drilling team to make quick decisions on were to place the well within the structure. This short paper will show the step change bought about in 3 of the wells drilled and the success and benefits realized by using long gauge PDC bits combined with a specialized short bearing pack motors, not only in the quality of the real time and recorded logs but in the over all bore hole quality as well. Introduction It was long recognized by the drilling hands in the 30's and 40's that running casing in vertical wells could be very problematic. One of the first theoretical attempts to explain what was happening down hole by Macdonald and Lubinsky in 1951 (Ref#1) gave rise to the "Crooked-Hole Formula". This basically recognized that a hole did not necessarily drill straight or in gauge and that the drift diameter of the hole could be significantly less that the diameter of the it that drilled it.

This paper describes the mobilization of a snubbing unit and blowout preventer (BOP) stack in the Middle East and their use to enable the control of a well with an underground blowout and surface broaching within a short time. The mobilization timeline is provided, along with details about how the snubbing unit and BOPs were integrated with existing equipment to enable re-entry into the blowout well. The procedures and equipment used to enable a stable rig up and well entry are discussed. The paper also describes the situation within the well and the procedures used to enable control. Changes to the original plan, the reasons for the changes, and the results are also described. Mobilization, rig up, and testing were completed within 12 days of receiving instructions to proceed. The well was controlled and left in a safe condition within an additional 14 days. The original plan had to be continuously reviewed and modified as more information became available during the snubbing operation. The original plan was to slip and shear the holed completion out of the well under pressure; however, as described in the paper, this plan was not implemented. The rapid deployment and use of the snubbing unit brought control to a deteriorating situation. Snubbing provided the fastest option to gain control of this well with an underground blowout and surface broaching.

This paper describes the planning, execution, improvements, and results from a multi-well fishing campaign using a snubbing unit on pressurized H2S wells for a national oil company (NOC) in the Middle East. A suitable blow out preventer (BOP) stack is shown for fishing coiled tubing, wireline tools, and milling along with the contingencies considered and how these were incorporated into the design of the stack. The challenges encountered during the execution phase are explained along with the solutions implemented. The key performance indicators used and how these improved the operational efficiency during the campaign are discussed. The well problems, desired results, and actual results of the interventions on the wells completed to date are shown.