Drilling the 16-in. section in Umm Gudair field in western Kuwait faces a lot of challenges while drilling. Challenges include drilling through severe loss conditions, destabilized shale, and deteriorating hole conditions. These conditions can result in hole collapse or lost in hole of the drill string that requires sidetracking. The objective of project presented in this paper was to develop an engineered solution to drill through the difficult zones, lessen nonproductive time, and reduce the total well cost. The solution proposed was to use casing-while-drilling technology with a drillable bit and drill through the fractured dolomitic limestone and sandstone formation while simultaneously setting casing. The drillable casing-while-drilling bit was specifically designed and engineered to conform to the formations in the field. The drillable casing-while-drilling bit is manufactured with a material that can be drilled out with either conventional roller cone or fixed cutter bits. A plastering process was used, which smears the cuttings generated by drilling against the borehole wall, seals the pores or fractures in the formation, and helps reduce fluid losses while maintaining well integrity. The successful implementation of 16 × 13.375-in. casing-while-drilling job in Umm Gudair field reduced well delivery time for the operator and saved 17 rig days with cost savings of 450,000 US Dollars considering rig rate only. The section was drilled successfully while encountering total mud losses through fractured dolomitic limestone and sandstone formations. Preventing the risk of losing the bottomhole assembly in the hole and alleviating the use of multiple cement plugs saved additional cost for loss-cure plugs to heal the loss-prone formations. After reaching the target depth, cementing, pressure testing of the casing were carried out successfully. Lesson learnt from the first job were applied in the subsequent job completing the section with faster ROP with substantial savings to operator. For both the jobs, drillout of the drillable casing-while-drilling bit using a fixed cutter bit and Rotary Steerable bottom-hole assembly were performed successfully, the drillout bit continued drilling to section TD in one run. With the successful implementation and the savings obtained by using this casing-while-drilling technology in the West Kuwait field, there is the potential for substantial annual cost savings, aiding the operator deliver wells in less time, and eventually increase production by increasing the number of wells drilled per year.

Reduced land slots availability for drilling of new wells, operator's focus to increase production, aim to reduce effective cost per barrel and to minimize the environmental footprint, worldwide drilling contractors/operators are looking for various solutions available to address these concerns. Drilling multilateral wells is one of the solutions to these concerns. This paper presents the process and steps followed in planning and decision making for drilling a multilateral well in one of the North field in Kuwait, which includes Identification of filed and understanding formation, Categories of multilateral wells and selection of level and types of multilateral well, Pre requisition of data for level 1 multilateral well, Selection of well slot and reviewing additional tools/service requirement, Selection of well trajectories for multilateral well, Selection of open hole junction point, Selection of section TDs, Review of directional BHA & its suitability for open hole side track, Well control scenarios, Well stimulation plans, Review of Coil tubing (CTU) operation for stimulation and tools requirement, Contingencies plan for reservoir section, Cost saving, higher production, environmental footprint, well completion days.

The Great Burgan reservoir is the largest sandstone oilfield in the world, it has been developed and produced since the 1930s. Historically developed through deviated wells, a new project of horizontal wells was initiated recently to produce from the UB3 reservoir unit. A pilot hole is usually required to identify the presence of productive sublayers and the depth of the oil-water contact (OWC), which must be avoided in the horizontal section. Elimination of the pilot hole would help to minimize the time and cost of development (Al Khalifa et al. 2020). The azimuthal ultra-deep resistivity mapping service (UDR) has proven its capability to eliminate the need for pilot holes by mapping reservoir boundaries and OWC on the fly, earlier than with traditional methods. This facilitates real-time geosteering to land the well in a single drilling run in the productive zone. Additionally, it helps to reduce non-productive time by making it easier to stop drilling and set casing above a target layer and to help optimize future well planning in field development. A feasibility study performed on offset wells showed promising potential from application of this method in the UB3. Real-time UDR geomapping detected multiple thin sand lenses on top of UB3 but showed that they were not of commercial capacity. The decision was made to continue drilling deeper for a larger sand layer. The UDR detected a massive sand below the smaller lenses and the well was landed in it. Early mapping also helped to optimize the landing with the desired inclination and dog-leg severity. The OWC was detected ~35 ft TVD below the landing point. Without UDR it would have been impossible to detect the OWC and very challenging to perform an accurate landing. The target could have been missed by landing either too shallow or too deep or with the wrong inclination. Following the landing of the well the lateral section was drilled through upper and lower lobes of the massive sand with a total cut of 1649 ft MD. This comprised 450 ft MD of upper lobe, 350 ft MD of transition interval, and 637 ft MD of lower lobe inside BU3, with an average porosity of 30 p.u. and a water saturation of less than 10%. Formation pressure tests measured mobility of up to ~3.4 D/cp. This case study demonstrates that utilization of the ultra-deep resistivity mapping service enabled a new approach to drilling lateral wells in the Burgan field development, improving reservoir insight and reducing well drilling time and cost.

Umm Ghudair Field is one of the major oil producing fields in West Kuwait. Oil was discovered in 1962 in the Lower Cretaceous Minagish Oolite Formation and more than 200 wells have been drilled to exploit this reservoir since then. Stratigraphically, the formation is defined by three units; Lower, Middle and Upper. The lower and upper units are considered non-reservoirs, while the middle one is hydrocarbon bearing. However, because of the continuous production over the past 50 years, the filed started to show a variable rise in its oil water contact (OWC). Consequently, this uncertain OWC rise has impacted the planning and production of the newly drilled wells (deviated and horizontal). Several recently drilled wells showed water breakthrough much earlier than expected. To address this challenge and with an attempt to proactively predict the current OWC depth in the new wells to be drilled, Kuwait Oil Company (KOC) decided to try the new High Definition Reservoir-Mapping-While-Drilling (HD-RMWD) technology in one of the horizontal well in their field. The objective was to assess the potential of the technology in detecting and mapping the current OWC while landing the well in the target. Due to the ultra-deep detection range of the technology (in excess of 200 ft), the landing point could be adjusted proactively and early enough to accommodate any unexpected OWC depth changes in the field.