Hawy, Ahmed El (Schlumberger) | Picha, Mahesh Shrichand (Is'Haq Habsi, PDO) | Soliman, Fathy (Is'Haq Habsi, PDO) | Haeser, Patrick A C M (Is'Haq Habsi, PDO) | Hadhrami, Moosa Al (Is'Haq Habsi, PDO) | Kindi, Adil Al (Is'Haq Habsi, PDO) | Eljenni, Mounir (Is'Haq Habsi, PDO) | Busaidi, Ibrahim AL (Schlumberger) | Busaidi, Adil Zahran Al (Schlumberger) | Bazara, Magdi (Schlumberger) | Omara, Ahmed Sadig (Schlumberger)
As conventional drilling learning curves mature from drilling simple vertical wells to deviated wells to complex multilateral horizontal wells, the boundaries needed to be broken to reach much deeper depths rather than consuming the time in drilling multiple shorter laterals. Horizontal ERD wells in Qarn Alam cluster were planned to be drilled in four sections where the 17.5-in section is drilled vertically followed by a deviated 12.25-in section and continued by landing in 8.5-in section and finally the 6.125-in horizontal lateral. Many attempts of performance improvement initiatives were executed over many years however there were always flaws and inconsistency in drilling performance delivery. As the need of ERD grew, a detailed offset wells analysis had to be performed where all the deficiencies and issues had to be pin pointed, RCA (Root Cause Analysis) had to be performed and plans for success had to be laid out. From challenges achieving required dog legs in the top sections with increased risks of axial and lateral vibrations, to the difficulties faced in the landing section drilling through unconsolidated and reactive shales, to the difficulties transferring weight to the bit at deeper depths in the horizontal laterals drilling highly porous zones of sticky limestones resulting in severe torsional vibrations. A new approach of drilling had to be executed with a renovated set of drilling parameters envelopes, revised trajectory designs, re-engineered BHA designs, right choice of fit for purpose bits and effective real-time performance monitoring.
Zampetti, Valentina (Shell International B.V) | Perrotta, Sonia (Shell International B.V) | Chaari, Ghassen (Shell International B.V) | Krayenbuehl, Thomas (Shell International B.V) | Braun, Matthias (Shell International B.V) | Neves, Fernando (ADNOC) | Hu, Jialiang (ADNOC)
The Aptian Shuaiba Formation is among the most important reservoir units in the Middle East. Despite being extensively studied in recent years (
An integrated and iterative analysis including regional geology, well and seismic data was conducted to unravel the internal depositional geometries and associated reservoir properties for the Shuaiba Formation in the western region of UAE. In the study area, spatial distribution and geometry of the Shuaiba seismic facies was mapped in detail using full-stack reflectivity, discontinuity, curvature and spectral decomposition seismic attributes and further integrated with available well data and analogues. The Shuaiba Formation is expressed on seismic by mounded facies characterized by an irregular appearance, with discontinuous outline of sub-transparent reflectors, crossing reflectors and a larger thickness than the surrounding facies. Reflectors may locally coalesce and form mounded features up to 70 ms thick. The areas between mounds are characterised by sub-parallel to inclined reflections. The latter could be interpreted as clinoforms, prograding from the isolated nucleation areas to their deeper surroundings. The base of the mounds is located just above the top Thamama B/base Shuaiba reflector and the top coincides with the top Shuaiba. Well data suggest that these mounds consist usually of
Verma, Chandresh (Baker Hughes Integrated Operations) | Rodriguez, Fernando (Baker Hughes Integrated Operations) | Qasin, Qazi Mohammed (Baker Hughes Integrated Operations) | Chaaouri, Aramco Mohsen (Baker Hughes Integrated Operations) | Akel, Sami (Baker Hughes Integrated Operations) | Akiki, Ghassan (Baker Hughes Integrated Operations) | Afolabi, Jonathan (Baker Hughes Integrated Operations)
Energy consumption and demand are steadily increasing. Hydrocarbons have been an important energy provider for several decades, but production from mature oil and gas producers is declining. Great effort is put into improving oil and gas reservoir recovery to meet this rise in energy demand.
In the subject reservoir where the pay zone is a thick, multi-layered limestone, characterized by low-permeability; conventional techniques yield lower than expected production results.
To improve production and the ultimate recovery of the field, extended-reach drilling (ERD) wells with long horizontal multilaterals (Quad and Penta-laterals well types) were drilled to attain maximum reservoir contact (MRC), ranging from 10 to 14 Km. These wells equipped with intelligent completions, enable uniform contribution along the extended horizontal intervals. This contribution is achieved through better flow management of the different sections of reservoir contact, reducing operational drawdown pressures, and delaying gas and water breakthrough. The result is high well potentials, improved long-term performance of sweep and recovery, and increasing net worth of the drilling investment.
This paper presents the lessons learned from hundreds of ERD multilateral wells drilled in the field, including integrated operations, progressive approaches and innovative applications, improved drilling practices on a continuous basis, and the tools and techniques used to drill and complete the wells safely and efficiently.
These efforts achieved a milestone record rate of penetration (ROP) in the Middle East of 5,000 feet per day, and as a direct result contributed to minimizing well delivery time by 35 % and average 25% reduction in well cost in an always challenging drilling environment.
The design approach, job execution and evaluation of drilling performance are presented in this paper; as well as key technical challenges and risks encountered during planning and execution stages and how these were mitigated and overcome for MRC improvement and optimization.
Well construction was challenged to meet the complex multi-lateral with long cantilever sections.
The MRC optimization schemes applied in the field resulted in dramatically reduced days of drilling operations that led to millions of dollars in project savings and the achievement of world class drilling records.
Al-Awadi, A. M. (Kuwait Oil Company) | Haines, T. (Badley Ashton and Associates) | Bertouche, M. (Badley Ashton and Associates) | Bonin, A. (Badley Ashton and Associates) | Fuchs, M. (Badley Ashton and Associates) | Deville De Periere, M. (Badley Ashton and Associates) | Challa, P. (Kuwait Oil Company) | Zaidi, S. (Kuwait Oil Company)
The Late Albian Mauddud Formation of North Kuwait is composed of inner ramp carbonates and deltaic clastics. It hosts prolific hydrocarbon reserves in Kuwait and across the Arabian Gulf region where the reservoirs are typically the carbonate deposits. Accurately predicting the reservoir properties in the Mauddud Formation is challenging due to the non-unique wireline signatures, which result from the inherent diagenetic heterogeneity and complexity. 385ft of continuous FMI image log data, collected from a single well covering the entire formation in a north Kuwait field, has been analysed to assess its potential to characterise and extrapolate the sedimentological, diagenetic and reservoir characteristics into uncored wells. Nine distinct image facies have been defined, each of which display a specific image fabric. The image facies have been calibrated with core, thin section petrographic observations and core plug data to aid reservoir quality predictability.
The study shows that gross sedimentological and diagenetic characteristics observed in the core, including laminations, patchily distributed cements and bioturbation are identifiable in the image logs. The image facies display mottled, laminated or massive fabrics. The argillaceous, fine-grained deltaic clastics, which are non-reservoir, correspond to the finely laminated image facies, however, these deposits are easily identified in uncored intervals by their distinct wireline log signature. The mottled image facies, which is associated with patchy calcite and dolomite cemented carbonates, are subdivided into six categories primarily based on the mottling size. This work establishes a systematic relationship between the mottling size and the grain to micrite matrix ratio of the deposits, and hence, the depositional setting. The finest mottles, corresponding to the smallest cement patches, are typically associated with micrite-supported lithofacies representing deposition in a low-energy inner ramp environment, while the coarsest mottles are principally observed in the grain-supported carbonate lithofacies, which are prevalent in higher energy inner ramp environments. This relationship, which possibly relates to differences in the bioturbation and/or diagenetic overprint of the deposits, is used as a proxy to interpret the depositional energy in the Mauddud Formation. Cross-laminated and massive image facies are also locally identified and are predominantly associated with high-energy shoal complex carbonates. The image facies, in part, also predict the distribution of some of the best porosity and permeability in this formation, notably in the finer mottled image facies where reservoir quality is good to moderate (HeΦ 12.5-25.8% and Kair 1.04-22.4mD). In the coarser mottled image facies, reservoir quality is heterogeneous, but can be comparably good.
Using this approach, the gross rock and reservoir properties of the Mauddud Formation can be partly characterised using FMI data alone. The scheme will be refined using further core-calibrated FMI datasets from additional wells to ultimately aid the prediction of reservoir quality at field-scale.
Recipients of the 2017 SPE international awards will be recognized at the Annual Reception and Banquet held on Tuesday, 10 October. The 2017 SPE ATCE will be held in San Antonio, Texas. Honorary Membership is conferred on individuals for outstanding service to SPE and/or in recognition of distinguished scientific or engineering achievement in fields encompassed in SPE's technical scope. Honorary Membership is the highest honor SPE confers upon an individual and is limited to 0.1% of SPE's total membership. Akhil Datta-Gupta is a professor of petroleum engineering at Texas A&M University. He worked for BP Exploration and Research from 1986 to 1990 and the Lawrence Berkeley National Laboratory from 1992 to 1994 before joining Texas A&M in 1994. Datta-Gupta was elected to the US National Academy of Engineering in 2012 for "developing the theory and practice of streamline simulation for fluid flow in heterogeneous reservoirs." Datta-Gupta received SPE Distinguished Membership in 2001 and several other honors from SPE, including the John Franklin Carll and Lester C. Uren awards. He was named an SPE Distinguished Lecturer in 1999-2000, a Distinguished Author in 2000, an outstanding technical editor in 1996, and was awarded the Ferguson certificate in 2000 and 2006. He has published more than 100 peer reviewed technical papers and 4 books, including an SPE textbook. Datta-Gupta holds a PhD in petroleum engineering from the University of Texas.
Wellbore tortuosity or spiraling can lead to the trapping of a cuttings bed in a trough of a tortuous hole, thereby leading to poor hole cleaning in extended-reach drilling. The objectives of this study included quantitatively evaluating the influences of wellbore tortuosity on hole cleaning and cuttings-transport behavior in extended-reach drilling. In addition, the study provided a recommendation of effective drilling practices. The study involved performing hole-cleaning-optimization studies for an extended-reach well with a long horizontal section aiming for maximum reservoir contact, by use of a transient cuttings-transport simulator. The planned trajectory of the well was assumed to have a certain degree of wellbore tortuosity in the horizontal section. The pump rate and bottoms-up circulation operation were optimized on the basis of parameter studies and additional transient simulations by considering the effects of penetration rate and variation in cuttings size.
Simulation results indicated the formation of a considerably high cuttings bed, particularly in the downdip intervals (updip in mudflow direction) at an insufficient pump rate; one-third to one-half of the drillpipe diameter could be potentially buried in a cuttings-deposit bed, and this can result in a packed-off hole or stuck pipe. A higher rate of penetration (ROP) can also cause insufficient hole cleaning. In this case, controlled drilling that maintains a reasonably low penetration rate may be effective. Furthermore, borehole breakout may enlarge hole diameter and generate large-sized cuttings. Both of these can have negative impacts on hole cleaning, and, thus, borehole stability and smooth wellbore-trajectory controls should be carefully considered. To clean these holes, frequent bottoms-up circulations were effective at each stand of drilling even if the optimization of other drilling parameters was limited. The findings also revealed that accumulated cuttings in a tortuous wellbore were trapped in the trough of the hole, and that the bed height of locally trapped cuttings in the downdip intervals could be much higher than that indicated by previous studies.
Shallow hazard migration post-cementing is a well-known and costly problem worldwide. It is extremely difficult to fix once it has occurred since limited remedial options are available with marginal success rates. Its causes are easy to understand yet it needs careful planning to prevent it. Post-cementing shallow water flow and gas migration may occur due to several collective causes such as poor fluid displacement efficiencies, losses prior/post or during cement placement, and/or underperforming slurry properties.
Previously proposed solutions focus only on one of these challenges with various success rate depending on well conditions. Addressing all these challenges together is essential for successful prevention. Due to the nature of these wells containing the high probability of flow from these shallow hazards, the clearances between pore and fracture pressures are narrow. This makes the common mud removal approach of displacement mechanics challenging. It also requires a delicate balance between maintaining sufficient hydrostatic to remain above the pore pressure of the flow zone and losing to the weak formations. Independent of these boundary conditions, the slurry needs to have a given set of performance properties to prevent any influx into the annulus.
This paper discuss the successful implementation of cementing solutions and control measures used to prevent shallow hazards migration in Saudi Arabia. This manuscript will discuss the field implementation and operations documenting the step changes success.
The eastern flank of the Rub' al-Khali region (“the Empty Quarter”) is home to the Shaybah and Ramlah fields, and surrounding fields in which there is exploration for hydrocarbons. In the post-Lower Cretaceous time, this region experienced multiple larger sedimentary cycles, with the first cycle terminated by the pre-Aruma Unconformity. The next major cycle took place from the Late Cretaceous into the Middle Eocene period with predominately carbonate deposition, culminating in mixed carbonate-evaporitic systems. This cycle is comprised of the Aruma, Umm Er Radhuma (UER), Rus, and Dammam formations, which include the current aquifer systems in this area.
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.
The objective of drilling a well is to accommodate the completion string designed to optimize reservoir production. Streamlining a completion design for a mature field maximizes the chances of achieving the well objective with minimal drilling challenges. Therefore, introducing a new completion technology requires reevaluating the drilling procedures and practices to accommodate for the modified completion, and this is more true when running new completion designs into the open hole as opposed to cased hole completions. The Saudi Aramco drilling team were faced with the challenge of executing a multi-lateral well plan that will allow for running three open hole completions that will segment the open hole laterals and provide active control and monitoring capabilities for each segment. Such a completion requires a complex power and telemetry system that can energize all the segmented lateral completions including the ones that are deployed through the windows. The open hole laterals must be conditioned properly to successfully run the completion components in the open hole without restriction, and land the completions at the pre-planned target depths.
The main power supply and telemetry conduit between the upper completion and the open hole completions is a cable cemented behind the 7 in. liner. This presented several challenges such as running and cementing the liner and milling the windows without intersecting the cable, which would jeopardize the success of the entire completion. The team addressed the challenges by developing procedures to properly execute the mentioned operations while maintaining the integrity of the power system and land the completions at depth. This was confirmed by conducting tests at various stages throughout the implementation process.
An integrated project such as this requires focused collaboration between the drilling and completion teams because the traditional practice is to drill to total depth then complete the well, although this unique completion design requires a drill-complete-drill-complete sequence as the well progresses.
In addition to highlighting the key factors in managing and implementing such a well construction project where various disciplines are interdependent and require continuous coordination, the paper will summarize the modifications applied to the drilling procedures to achieve the objective of the subject well. The emphasis will mainly be on three operations: Under-reaming while drilling the 8-1/2 x 9 in. hole section, hole preparation prior to running the open hole completion, and the implementation of a unique cable avoidance procedure during conventional window milling operations.
Wells with extended-reach multilaterals have improved reservoir contact and have opened the opportunity for well-placement and -drilling optimization. Since the early 2000s, the number of maximum-reservoir-contact wells has increased substantially, and the benefit of these wells is being realized at the early implementation stage. To enhance the performance of these multilateral wells, intervention operations in the laterals are required. Stimulation, data acquisition, and other operations are required to optimize the production from the laterals; however, accessing the lateral of any wellbore for intervention in a reliable manner is still a challenge. The present paper describes the development of an intelligent, real-time controllable tool, the well-lateral-intervention tool (WLIT), that can identify a lateral junction and steer an intervention/surveillance string into it. The WLIT is designed to be deployed by use of either coiled tubing or e-line (with the help of a well tractor for extended-reach horizontal deployment) for logging and/or stimulation purposes. This application provides the ability to increase the quantity and quality of information collected from the entire well--main bore and the multiple laterals individually--to obtain the best answer. The discussion is dedicated to the development stages of the tool and field-trial-test results. The WLIT has two versions. The first version is called "wired," which accommodates specific logging tools that are compatible with the WLIT design, whereas the second version, "wireless," allows the use of all types of logging-tool strings from any third-party provider. The test results highlight both versions of the tool. The WLIT sensory equipment and the control environment are described, and results from the field-trial tests are presented.