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The Saudi Arabian Oil Company (Saudi Aramco) operates one of the principal high profile extended reach drilling (ERD) projects in the world. This is accomplished through the development of a sizable number of horizontal wells categorized according to the total depth. Wells with the shortest vertical displacement have been significantly optimized during the project execution thereby reducing the room for enhancement. The drilling engineering team conducted a comprehensive evaluation of the existing casing scheme and problematics along the M field. A new approach was devised to redesign wells with a total depth up to 17,600 ft. The aim was to achieve a substantial improvement in drilling performance and potential savings for the remainder of the project.
ML-1 and MO-1 were selected as candidates to implement the novel alternative; both drilled from different platforms where several wells have been previously completed using the standard design. Drilling troubles, such as loss of circulation and hole instability, occurred during the execution of such wells leading to major lost time. The solution comprised the optimization of the well trajectory, slim-down the upper hole sections and combine the lower ones, drill longer intervals and set casings deeper to cover problematic zones without compromising the well integrity. The detailed engineering study included a probabilistic analysis to evaluate the economic viability of the landmark application.
Two wells were successfully drilled and completed applying the downsizing strategy. The impact of anticipated challenging events in both 12 1/4-in and 8 1/2-in holes was decreased as a result of the new design. The implemented preventive plans led to a rapid elimination of encountered challenges. This optimization produced a combined 27% reduction in drilling time, and minimal non-productive time (NPT) with associated global cost savings of 39% compared to a large hole string design.
Finally, this new approach in a still ongoing project along with the feasibility of extending it to other areas will lead to potential improvement in well delivery and operating cost.
Muñoz, German (Saudi Aramco) | Dhafeeri, Bader (Saudi Aramco) | Saggaf, Hatem (Saudi Aramco) | Shaaban, Hossam (Schlumberger Oilfield Services) | Herrera, Delimar C. (Schlumberger Oilfield Services) | Osman, Ahmed (Schlumberger Oilfield Services) | Otaremwa, Locus (Schlumberger Oilfield Services)
To access the reservoir in a large Saudi Arabian development field, the operator is required to drill an intermediate 5,000 ft to 6,000 ft directional hole section with dogleg severity (DLS) varying from 2.5°/100 ft to 3°/100 ft. The commonly drilled 12¼-in. borehole crosses several interbedded formations comprised of limestone, shale and sands, and it is associated to a variety of hole problems, which present repeatedly in the offset wells. The main objective for the operator was to mitigate the problematic by defining alternative and suited drilling technologies. Among them, Saudi Aramco found that the recent developments in the directional casing while drilling (DCwD) technology may well provide an effective method for diminishing the associated nonproductive time (NPT).
The drilling engineering team conducted an extensive evaluation of the problems across this section, including wellbore stability, water flow, and loss of circulation; tight hole/stuck pipe incidents, severe bit/stabilizer wear while drilling abrasive sands. After a promising technical and engineering evaluation, followed by a detailed risk assessment aiming to determine the potential of the application, the selected well was planned and executed using the DCwD service.
This paper outlines the process carried out during all stages through the final deployment of the first 9?-in. DCwD application in Saudi Arabia, and how it successfully aided in achieving the goals by reducing the impact of some of the problems experienced while drilling the same section in previous wells in the field. Likewise, the information provided will serve as a starting point for the design and construction of subsequent wells leading to further improvement in drilling performance. Best practices and lessons learned from this implementation are expected to become a model and the know-how transferred to other areas where comparable drilling events occur.
The technological benefits have been recognized by the operator and this application reestablished DCwD as a viable technology to address a number of challenges common in many of the Saudi Arabian oil and gas fields.
Muñoz, German (Saudi Aramco) | Campos, Marlio (Saudi Aramco) | Mousa, Ahmed (Saudi Aramco) | Osman, Ahmed (Schlumberger) | Elsadig, Mohammed (Schlumberger) | Al-Massari, Bandar (Schlumberger) | Askar, Oussama (Schlumberger) | Verma, Vikhyat (Schlumberger) | Almry, Faisal (Schlumberger)
One of the highest profile extended reach drilling (ERD) oil projects in the world is presently operated by Saudi Aramco. It is being developed with a large number of horizontal ERD wells targeting a carbonate reservoir; classified according to the well objectives as producers or injectors. The wells are being drilled from land locations, artificial islands and offshore platforms which increase the complexity and challenges of the project. The production and well delivery requirements for the development phase were planned with very ambitious targets. Therefore, multiple drilling and completions technologies have continuously been pursued to achieve the planned schedule.
During the past years, the drilling team planned to take this project to the next level by drilling and completing the longest horizontal ERD well in Saudi Arabia (M-1) to a total depth (TD) of 37,042 ft MD with an open hole completion of 10,002 ft. To achieve this and to push the drilling envelope to that extent, many drilling challenges were expected and new approaches, procedures and technologies were deployed to overcome them.
The main challenges were related to torque and drag limitations for drillpipe and casing runs, losses and wellbore stability considerations, hole cleaning and equivalent circulating density (ECD) management for stuck pipe prevention, drilling dynamics in harsh drilling environment, logging data transmission at deep intervals of the well and pushing the limit of drilling performance and equipment reliability. To overcome them, considerable well design changes were introduced, along with customized procedures and new technologies to ensure the safe and efficient delivery of this well. First, the well design was optimized and changed from a standard design to a deepened casing design, to cover unstable formations. Second, the drill string design loads were simulated through comprehensive torque and drag modeling to determine the components specifications and to develop safe running procedures. Third, well specific ERD hole cleaning procedures, ECD management guidelines and tripping roadmaps were implemented to deliver optimum hole condition and minimize stuck pipe risks. Finally, multiple drilling technologies, including rotary steerable systems, telemetry tools, sidetracking equipment and mud additives, were introduced to realiably deliver the well objectives.
The optimization changes in the well design, procedures, practices and drilling technologies have resulted in delivering a number of records which include: drilling the longest well in Saudi Arabia safely and efficiently, installing the world's deepest 7-in. solid liner, achieving the world record for the deepest 6 1/8-in. lateral section and the longest 6 1/8-in. section for the project; and successfully running and setting the world's deepest 7-in. cased hole whipstock. These records are considered a step change for Saudi Aramco drilling operations and a new milestone for the ERD drilling industry.
Okot, Mike (Saudi Aramco) | Campos, Marlio (Saudi Aramco) | Muñoz, German (Saudi Aramco) | Alalsayednassir, Alawi G. (Saudi Aramco) | Weber, Matt (Frank's International, LLC) | Muneer, Zahid (Schlumberger)
This paper was also presented at the 2015 SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition as SPE-176286-MS.
Saudi Aramco operates one of the largest offshore oilfield developments in the world. This field is made up of 41 kilometers of causeway, 3 kilometers of bridges, 27 drilling islands, 13 offshore platforms, and 16 onshore drill sites. The magnitude of the field has pushed cutting edge technology and processes to the forefront of the industry. This new development has driven achievements in multilateral and extended reach directional wells. One challenge the operator faces is to maintain proper hole cleaning in extended 8½ in. tangent sections at a 85-87° inclinations, which are drilled in excess of 10,000 ft.
Historically, drilling very long tangent sections required the use of several tandem sweep pills, wiper trips, and reaming/back reaming to maintain hole quality and efficiently remove cuttings bed from the wellbore. The negative effects of poor hole cleaning can lead to tight intervals, increased torque and drag, and eventually stuck pipe.
In an effort to drill efficiently, utilization of a new technology to increase the cutting removal was trial tested on well A1 from an onshore location of the field. The ERD well, A1, was drilled to a total depth of 30,480 ft MD (8,650 ft TVD) into a stratigraphic environment composed of limestone, shale, and siltstone. The objective of the trial test for the tool was to improve the drilling efficiency. To obtain the best possible hole cleaning, a simulation was performed by placing the tools every three stands along the tangent section in the 8½ in. hole section.
The goal of the trial test was to achieve the following:
Enhance hole cleaning by removal of cuttings bed.
Reduce the frequency/number of tandem sweep pills.
Reduce the frequency/number of wiper trips.
Reduce torque and drag and compare it with the offset wells.
Reduce drilling cost.
A service company installed a cuttings flow-meter system at the shakers, which was used to evaluate the hole cleaning efficiency and performance of the hole cleaning tools. This paper will demonstrate the systematic methodology, which Saudi Aramco and the service company used to approach the utilization of the hole cleaning tools to achieve a clean hole in well A1.