Optimizing resources and pushing the drilling limits to tap into deeper reservoirs at minimal cost has always been the primary objective of many operators worldwide. Moreover, the prolonged current market conditions are pressurizing every stakeholder involved within the well-delivery process to reduce time and the associated costs like never before. This paper deals with an Offshore Artificial Island project where the drilling limits were constantly challenged by adopting new technologies and practices in an extended-reach drilling (ERD) campaign. The complexity of these extended-reach wells was managed effectively with excellent planning and execution. Implementation of new and existing technologies and the adoption of revamped operational practices has managed the challenges of equipment capabilities, torque and drag, ECD, wellbore stability, hole cleaning and stuck pipe avoidance to name a few. The project drilled longer wells at less costs. This approach has resulted in drilling and completion of wells comfortably within the equipment-rating envelope. Additional technological means such as newly developed lubricant and mechanical drill pipe torque reducer subs helped reduce the friction factor and eliminate drill string buckling. Existing technology in the bottom-hole assembly (BHA) minimized the tortuosity in the wellbore, along with transmitted real-time downhole drilling data (Torque, Weight on Bit, Mechanical Specific Energy, and Equivalent Circulating Density) which helped in active drilling parameters optimization for efficient drilling. Similar technologies and practices were used in landing the completion string. The geo-mechanical studies undertaken at the concept stage and later revised against the offset well information helped in drilling the troublesome shale formations with no associated events. Specific importance was given to maximizing the hole cleaning by having the right tools in the BHA that could accommodate higher flow rates while using a tandem drill string for lower hydraulics. In addition, the newly formulated field / formation specific drilling and reaming practices minimized the stuck pipe, saving approximately 10% in overall well costs. This paper discusses the successful drilling of a number of offshore ERD wells with various complexities and tailored solutions with minimal downhole problems and within continuously revising planned times and budgets. The lessons learned and techniques associated with drilling of extended-reach wells at lower costs will be detailed in this paper. This information would give insights and considerations to all stakeholders who intend to drill extended reach wells or challenge their current limiters. This proven successful methodology and its results are considered a benchmark for the nearby fields in the region.

Directional drilling from artificial islands has become a common offshore practice in the United Arab Emirates, looking to minimize footprint while optimizing cost to reach maximum number of targets from a single location. This drilling practice brings some challenges such as torque and drag limitations, which is vital in order to safely reach wells total depth in well profiles with a high departure. The purpose of this paper is to discuss in detail the successful implementation of torque reduction techniques, focused on case histories from an artificial offshore island in the United Arab Emirates. During the planning phase, Drilling Engineers estimate expected torque and drag for the different sections based on modeling and historical data, this process is key to assess the limitations and initiate the process of evaluating the different torque and drag reduction techniques to be implemented based on the application. The case histories presented in this paper show the successful implementation of proven torque and drag management techniques, such as; well profile optimization, torque reduction subs, deployment of lubricated mud, use of real-time directional data to minimize hole tortuosity, and deployment of Rotary Steerable Systems from top to bottom for improved hole quality. There are different factors considered in the planning phase that make torque and drag management crucial, but drill pipes torque limitation was the main challenge to overcome in order to reach planned total depth in the case histories discussed in this paper. Wells trajectory and BHA optimization played an important role during the execution phase, as well as the deployment of lubricated mud and torque reduction subs which in conjunction provided an overall surface torque reduction of up to 28%. The implementation of different torque and drag reduction methods are illustrated with the modeling results and actual drilling data collected during the drilling of these wells. Information and data discussed in this paper can serve as documentation to aid in the planning phase for wells with similar challenges.

Because environmental regulations are rapidly evolving towards stringent requirements, oil and gasoperators are confronted with a great challenge of disposing drilling waste, especially when operating on an artificial island located 120-km offshore and under a Zero Discharge Policy. The paper describes an innovative engineering solution that significantly reduces the time, cost and the associated safety hazards with disposing of the cement waste generated from primary cementing operations and drilled cement cuttings. The earlier disposal process implemented on the island included collecting, storing, and shipping the cement waste to an onshore treatment facility. This process was proven to be cumbersome, time-consuming and extremely expensive. Additionally, external factors such as logistics constraints, weatherconditions, and storage skips availability had a direct negative impact on the process, resulting in a massive accumulation of waste on the island. On the other hand, the newly developed disposal process utilizes existing resources, with minor modification, within the artificial island. A step-by-step procedure was developed to dispose all excess cement and drilled cement cuttings generated without any negative HSE impact. A pilot trial was performed successfully by injecting the cement waste into the shallow loss zone through the annulus, and therefore, the process was generalized to both island and found to be safe and efficient operationally and economically. The new innovative method simplifies the disposal process to a one-stage operation that is performed along with the primary cementing operation. By implementing the process, no cement handling on surface is needed, resulting in a 90-percent drop in the cost.. The number of people involved is reduced as well. Consequently, a reduction in the hazard exposure and the potential lost time incident (LTI) is achieved.

Well integrity is becoming more challenging with drilling of deeper, highly deviated and horizontal wells worldwide while the current market scenario is driving every stakeholder to execute their scope of work under ever revising AFEs. The scope of this paper is to present an optimized approach to improve quality of cement jobs while having a good long term zonal isolation across all the targeted formations and further eliminating the additional costs required for remedial jobs. There are various challenges that need to be dealt with when cementing complex wells such as uneven cement distribution around the casing due to insufficient mud removal, inadequate hole cleaning and poor casing standoff. All these challenges were addressed by in-house developed optimization methodology. The elements of this methodology that positively influenced the quality of the cement bond were (i) Optimizing the rheological hierarchy between the cement, mud and spacer design to create optimum flow during the cement job (ii) Improving hole cleaning efficiency by applying tailor-made spacer technology with aid of modeling software (iii) Optimizing the centralizer profile by including non-survey stations. The in-house developed optimized methodology has yielded excellent results with significant improvement in the cement bond logs when compared to the offset wells. This paper will present the methodology adopted in detail along with the field example of a well in an offshore island that has measured success against the key improved elements. The rheology of the fluids was adjusted to improve the fluid displacement in the analytical software which has played a big role in improving the hole cleaning efficiency. In addition, application of tailored Spacer design has not only showed improved mud removal effectiveness but also helped with reducing the channeling alongside the best optimized centralization found in the field in terms of type, quantity and placement across various formations and direction profiles along the well bore. This paper will also compare different logs in the same field to show the improvement against the new methodology and practices adopted that helped in achieving complete zonal isolation across all formations. The new optimization methodology has resulted in significant improvement in outcome of cement logs across production casing in offshore island indicating an excellent zonal isolation and adherence to well integrity requirements. The key elements that were improved are now being adopted across all the jobs in the field and nearby fields.

This paper seeks to demonstrate how the use of real-time downhole drilling data can help facilitate the timely, well-informed decision to pull out of hole (POOH) if the rate of penetration (ROP) reduces beyond expectation. The traditional decision process starts with offset ROP comparison. If the ROP is lower than expected, then typically there are two scenarios: either the drill bit has become dull or the formation is harder to drill than expected. If the first scenario is suspected then a cost-benefit analysis is performed whereby the remaining footage is assessed and the time to drill to section TD with the current ROP is calculated and compared to the cost of a new drill bit, rig time and the cost of round tripping to change the bit. However, when the bit is on surface and seen to still have good cutting structure then the round trip has been a waste of time and money and more patience should have been exercised in keeping the drill bit on bottom. With real-time, downhole drilling data it is possible to assess the drillability of the formation and estimate the dull condition of the bit. Primary parameters that are used for this assessment are downhole weight on bit and downhole torque, and their relationship to one another. In addition, the trend of the downhole mechanical specific energy is evaluated. The first case study under discussion was drilled in 12¼-in. section, offshore UAE field. For the initial 4,500ft the average ROP was 80ft/hr, at which point a dramatic decrease in ROP was observed. A reduction in ROP was expected at this point because of formation change, but the magnitude of the reduction was much greater. Because the ROP was expected to reduce, the drilling continued with some short-lived increases in ROP. After a sustained time period of low ROP the decision to POOH was made, when the drill bit was on surface the dull grade was 1-6-HC-S-X-I-RO-PR. Upon evaluation of downhole drilling data with the aid of hindsight regarding eventual dull grade it was seen that there were clear indications that the bit was no longer effective and the decision to POOH should have been made. The time period that elapsed between the drill bit becoming damaged and POOH was 30 hours. This base case lesson learned was utilized on a subsequent well in the drilling campaign on an analogous application. By using this downhole signature a quicker, more effective POOH decision was made. The POOH decision in this case was made after just 2.5 hours compared to the 30 hours on the previous well. Once on surface, the dull grade of the bit was 2-7-WT-S-X-I-RO-PR.