Abdel Mageed, Mohamed (Khalda Petroleum Company) | Awad, Mostafa (Khalda Petroleum Company) | Hussein, Ahmed (Khalda Petroleum Company) | Osman, Ahmed (Schlumberger) | Siam, Mahmoud (Schlumberger) | Al-Kaabi, Mohammed (Schlumberger) | Rafik, Ahmed (Schlumberger)
Egypt's Western Desert is known to be a highly complex and difficult drilling environment. Drilling in this area suffers from multiple geological risks related to formation dip and hardness, faulting, interbedding, and abrasive lithology. These conditions have typically caused drilling problems and costly delays in wells delivery. Combined with the geological difficulties, differences in the implemented drilling practices and operational procedures have led to inefficiencies and the loss of some knowledge transfer among different drilling activities and field operations.
For a proof of concept in one of its fields, Khalda endorsed a drilling automation and operations benchmarking strategy to improve the well delivery time in one of its Western Desert fields. The strategy focused on on-bottom drilling activity as well as off-bottom practices and flat-time activities. One part of this strategy endorsed a real-time automated drilling optimization workflow for the on-bottom drilling activities whereby the implementation of a change-point algorithm dictates the optimum drilling parameters to obtain the best possible rate of penetration (ROP) within the rig and drilling assembly constraints and while operating within the safe drilling dynamics window for the assembly. This approach yields the optimum ROP and prevents any possible downhole equipment failure or premature bit damage. The other part of the strategy involved benchmarking the different rig activities while drilling or doing other mechanical operations to gauge the activity of the current well compared to the offset well. This highlights any inefficiencies that can be immediately overcome, areas of improvement, and key learnings for future optimization or implementation.
This strategy was implemented in a deep gas development well in a challenging Western Desert field with known problematic offsets. The results showed a step change in well delivery whereby the well finished 3 days ahead of plan and 7 days ahead of the offset well. The real-time automation technique for drilling optimization managed to show 24% on-bottom ROP improvement in one section, enabled completing another section with a one run less than offset, and managed to mitigate the harsh drilling dynamics to prevent downhole equipment incidents. Also, the activities benchmarking helped to develop standard drilling practices that reduced inefficiencies in off-bottom drilling activities by 50% and managed to highlight key learnings and areas of development for future wells. These results helped in validating the proof of concept set at the beginning of this pilot.
Abdelsamad, Hamdy (Khalda) | Muir, Douglas (Khalda) | Ibrahim, Abdelshafy (Khalda) | Mansour, Mahmoud (Khalda) | Osman, Ahmed (Schlumberger) | Rafik, Ahmed (Schlumberger) | Remah, Mostafa (Schlumberger)
Egypt Western Desert drilling fields have been known for harsh drilling environment, shock and vibrations conditions, interbedding and abrasive formations. Drilling assemblies have normally been suffering from excessive damages drilling through these conditions. Motorized rotary steerable drilling systems (RSS) were mostly considered the favored mechanism of drilling in this environment as they delivered higher drilling performance and mitigated vibration harmonics from transmitting higher up the string. Realtime shocks and vibrations data from directional tools was critical information to ensure safe and efficient drilling parameters and managing this harsh drilling environment without operating the equipment beyond its specifications.
In a recent western desert well, Khalda Petroleum Company (KPC) endorsed a new drilling strategy by modifying the conventional motorized rotary steerable drilling assembly from having only the RSS below the motor to having both the MWD and RSS tools below the motor. This modification was designed to enable KPC get closer measurements to bit with full transmission of all downhole data to surface to optimize the drilling parameters. The modification also aimed at increasing the bottom hole assembly (BHA) stability to prolong the run duration. To ensure reaching this goal, the design phase focused on two main directions. First, multiple finite element analysis modeling was implemented to ensure the optimum BHA stability and resistance to shocks and vibrations conditions. Second, KPC took needed considerations on the mud motor design, RSS operational procedures and MWD setup to ensure that these would fit properly in the new BHA design.
The strategy implemented has shown great success in delivering the section safely and with no incidents related to downhole drilling uncertainties and conditions. The section delivered the required directional profile with great precision and adherence. The new BHA actual data has shown high conformance to the modeled data and no shocks and vibrations conditions were encountered. The section was drilled in one run and was considered the longest and fastest directional run in its field. This has eventually lead to delivering this milestone section 3 days ahead of its planned timing.
Verma, Chandresh (Saudi Aramco) | ElKawass, Amir A. (Saudi Aramco) | Mehrdad, Nadem (Saudi Aramco) | ElDeeb, Tarek (Saudi Aramco) | Qazi, Muhammad Q. (Saudi Aramco) | Galaby, Amir (Schlumberger) | Salaheldin, Ahmed (Schlumberger) | Fakih, Abdulqawi Al (Schlumberger) | Osman, Ahmed (Schlumberger) | Hammoutene, Cherif (Schlumberger)
While ERD multi-lateral wells in a large Middle East field are typically drilled in six to seven well bore sections, drilling the 8.5-in curve and the 6.125-in lateral sections represents more than 50 % of the total time spent drilling the well. Challenges while drilling the curve section with a motor include difficulty transferring weight to the bit while sliding and differential sticking in the highly poros zones of gas cap. The laterals, which can extend up to 12,500 ft of reservoir contact, are characterized by medium to hard compacted carbonate formations with high stick and slip tendency. This represents several challenges for drill-bit design engineers given that aggressive cutting structures are preferred to generate good rate of penetration even though this often leads to high bottom-hole assembly vibration. Trajectory control, hole cleaning and long circulating hours also represent significant challenges.
This paper will present details of the engineering analysis performed to optimize both 8.5-in and 6.125-in wellbore sections.
For the curve section, the first step was to change the drill string from 5 in to 4 in which considerably reduced the time taken to change the string prior to drilling the laterals. This change of drill string was accompanied by the use of a rotary steerable system and a PDC bit. This was a combination that had never been implemented since the field discovery in 1968. These changes resulted in performance improvements in excess of 50 %.
For the laterals, the engineering analysis resulted in the need of a completely new bit design. The cutting structure was modified to provide a more aggressive bit to formation interaction, and the gauge contact with the formation was enhanced to maintain the bit and BHA stability. The resulting design broke the field rotary steerable ROP record by 28 %. The bit drilled the highest single run footage in the field (12,698 ft) at the highest ROP (96.93 ft/hr) with a rotary steerable system. This was further complemented by optimizing the drilling practices and well bore cleaning practices allowing the elimination of several conditioning trips within the long laterals which resulted in three days of savings in a three lateral well.
The paper will conclude with a discussion regarding the reduced injury exposure that resulted from changing the drill string earlier within the well and a review of further improvement opportunities.
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.
The Arctic is estimated to contain one-fifth of the undiscovered oil and gas resources in the world. Therefore it has the potential to be a major contributor to the world energy supply for decades to come. That is the reason many of the major oil and gas companies have been involved in exploration activities in the Arctic. However the Arctic is a unique environment often distinguished by the presence of ice and its general remoteness.
The Chukchi Sea is a southern extension of the Arctic Ocean bordered in the west by the East Siberian Sea and in the east by Alaska and the Beaufort Sea (
Statoil established a strong exploration portfolio in the Chukchi Sea since 2008 taking into consideration that operating in the Chukchi Sea involves managing a high number of risks. These risks include operating in a highly sensitive environment and extreme weather conditions. Also the limited infrastructure that can support exploration and drilling activities represent a challenge to operations, especially those related to emergency response.
Statoil completed seismic, shallow hazard and geotechnical coring surveys in the Chukchi Sea in 2010 and 2011. The company developed a robust HSE management system and emergency response plans to minimize the risks and to ensure that emergencies can be handled in the most effective way.
The emergency response plans started with a detailed risk assessment to identify all possible risks and their probabilities and consequences. Close collaboration with the Emergency Response group in the Houston office was established to compensate for the small size organization in Anchorage.
All operations were conducted successfully without any serious HSE incident. All relevant stakeholders including the native communities, federal agencies and the NGOs praised Statoil for the safe and efficient operations.
Khafji Joint Operations (KJO) is operating a key oil-producing field. This field has been developed extensively via horizontal drilling technologies for the past two decades. With excessive time and costs required for new offshore structure installation, the utilizing of the existing wells to drill re-entry horizontal wells became imperative and economical solution for further field developing, while minimizing the cost per foot required for well delivery.
Horizontal Re-entry operation in KJO has always been deemed totally undoable due to the fact that the 7 inch production liner in most of the old wells was tied back and cemented to surface. Hence, re-entry sidetrack operation would not have enough conventional casing strings options to allow the drill ahead to reservoir while having enough mechanical barriers to isolate the unstable shale zones. Also, slimming down the well design could not be a favored option as it does not accommodate the geo-steering, formation evaluation and completion requirements; which are essential for placing and producing the re-entry wells within KJO reservoirs.
To enable these re-entry wells, the Khafji drilling teams have performed a comprehensive study and risk assessment to re-define the strategy for drilling these horizontal re-entry wells. The new strategy divided the targeted re-entry wells into three main categories based on the challenges and complexity underlying each well. Each category was then assigned key enabling technologies in mud, drilling systems, optimum drilling practices, and completion techniques. These strategies along with enabling technologies were successfully implemented in a new horizontal re-entry campaign in KJO and have managed to deliver eight of these challenging wells during years 2013 and 2014.