Successful Implementation of Underbalanced Drilling to Maximize Recovery from a Tight Carbonate Reservoir in an Onshore Oil Field, Abu Dhabi, UAE

2010 ◽  
Author(s):  
Tayba Abdulrahim Al-Hashemi ◽  
Adel Mohammed Al-Hammadi ◽  
Hassan Sohdy ◽  
Mostafa Haggag ◽  
Omar Sultan Al Jeelani ◽  
...  
2021 ◽  
Vol 73 (07) ◽  
pp. 58-59
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202636, “Fishbone Stimulation: A Game Changer for Tight Carbonate Productivity Enhancement—Case Study of First Successful Implementation at ADNOC Onshore Fields,” by R.V. Rachapudi, SPE, S.S. Al-Jaberi, SPE, and M. Al Hashemi, SPE, ADNOC, et al., prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed. The operator’s first successful installation of fishbone stimulation technology was aimed at establishing vertical communication between layers in a tight carbonate reservoir and maximizing the reservoir contact. Furthermore, the advanced stimulation technology connects natural fractures within the reservoir, bypasses near-wellbore damage, and allows the thin sublayers to produce. This technology requires running standard lower-completion tubing with fishbone subs preloaded with 40-ft needles and stimulation with the rig on site. Introduction The operator plans to develop tight carbonate reservoirs as part of its production growth strategy. Field Q is a 35×15-km field under development with a phased approach. Phase 1 was planned and production began in 2014. Phase 2 is being developed by drilling wells using the pad concept. Reservoir A, a tight carbonate formation with low permeability ranging from 1 to 3 md and porosity from 15 to 25%, is part of Phase 2 development. The aver-age thickness of Reservoir A is approximately 90 ft across the field, with seven sublayers. The major challenge of Reservoir A development is poor vertical communication and low permeability. Based on appraisal-well data, the average production rate per well is approximately 200 to 400 BOPD with a wellhead pressure of 200 psi. Therefore, appraisal-well testing confirmed the poor productivity of the wells. In addition, the wells are required to produce to the central facilities located in a Phase 1 area 18 km away from Phase 2. In summary, each Phase 2 well is required to be produced against a back-pressure of 500 to 600 psi. Fishbone Stimulation Technology Fishbone stimulation technology is an uncemented-liner rig-deployed completion stimulation system. The liner includes fishbone subs at fixed intervals, and each sub consists of four needles that will connect the sublayers by penetrating into the formation. The typical fishbone completion after installation and jetting the needles in formation is shown in Fig. 1.


2008 ◽  
Author(s):  
Mohamed Benlacheheb ◽  
Adib Edris ◽  
Omar Sultan Al Jeelani ◽  
Salman Hassan Al Marzouqi ◽  
Maryam Al Sheehi ◽  
...  

2021 ◽  
Vol 73 (01) ◽  
pp. 20-22
Author(s):  
Trent Jacobs

In the midst of an industry downturn last year, the Abu Dhabi National Oil Company (ADNOC) reached a new oil production ceiling of 4 million B/D. The UAE’s largest producer has no intentions of slowing down. By decade’s end, ADNOC expects to have raised its maximum daily output by another million barrels. To cross that milestone, the company has set its sights on mastering the tight, thin, and unconventional formations that dot the UAE’s subsurface landscape. One of the places where such developments are hoped to unfold soon is known as Field Q. Found in southeastern Abu Dhabi, Field Q sits above a tight carbonate reservoir that holds an estimated 600 million bbl of oil. But with a permeability ranging from 1 to 3 millidarcy and poor vertical communication, the reservoir and its barrels have proven difficult to cultivate economically - until recently. ADNOC has published new details of its first onshore pilot of a “fishbone stimulation” that involved using more than a hundred hollow needles to pierce as far as 40 ft into the reservoir rock. The additional drainage netted by the fishbone needles boosted production threefold in the test well, as compared with its traditionally completed neighbors on the same pad. ADNOC ran the pilot in the summer of 2019 and by the end of the year saw enough production data to launch a wider 10-well pilot that remains underway. Based on a longer-term data set from these wells, the company will decide whether to leap into a fieldwide deployment of the niche completions technology. In the meantime, the petrotechnical team in charge of the test projects have issued roundly positive reviews of the fishbone technique in two recently presented technical papers (SPE 202636; SPE 203086) from the Abu Dhabi International Petroleum Exhibition & Conference (ADIPEC). “There is a chance that the fishbone-stimulated wells can avoid the drilling of multiple wells targeting different sublayers in the same zone,” said Rama Rao Rachapudi, listing one of several of the technology’s advantages over other approaches that were considered. The senior petroleum engineer with ADNOC, who is one of several authors of the papers that cover both the drilling and completions aspects of the pilot, shared during ADIPEC that his onshore team found motivation to test the technology after bringing in a batch of dis-mal appraisal wells. The fishbone system, also known as multilateral jetting stimulation technology, has been a specialized application ever since it was introduced just over a decade ago. Underscoring the potential impact of the current round of pilots on the technology’s adoption rate, ADNOC noted there were only around 30 worldwide fishbone deployments prior to this project. Most of those have been in the Middle East’s naturally fractured and layered carbonate formations - just like those of Field Q.


2014 ◽  
Author(s):  
Manhal Sirat ◽  
Xing Zhang ◽  
Janelle Simon ◽  
Aurifullah Vantala ◽  
Magdalena Povstyanova

2021 ◽  
Author(s):  
Kimikazu Tsusaka ◽  
Tatsuya Fuji ◽  
Motohiro Toma ◽  
Kengo Fukuda ◽  
Michael Alexander Shaver ◽  
...  

Abstract The 3,000 ft long lateral holes drilled through water-injected area in the carbonate reservoir in the offshore Abu Dhabi have been forced to implement hard backreaming. The abnormal extra operational time has been taken due to poor performance in the operation to pull out a bottomhole assembly after drilling to the total depth. The study aims to analyze root-causes of the hard backreaming through the carbonate reservoir in the studied field. The speed of tripping-out was analyzed every stand of drill pipe by using time domain data of movement of traveling block. The correlations between the speed of tripping-out and rock characteristics such as porosity and constituent minerals in rocks were investigated. Hole shape was analyzed in the representative intervals of low trip-out speed using 16-sector caliper derived from azimuthal density logging. Stress concentration around the borehole wall was also analyzed using geomechanical model. The investigation revealed that hole shrinkage due to plastic deformation of the borehole wall was the most possible root-cause of the hard backreaming in the carbonate reservoir. Namely, BHA had to ream up deformed borehole wall in tripping-out. From the viewpoint of rock characteristics, the speed of tripping-out was found to be lower in the specific geologic layers with higher content of dolomite. This is because dolomite rocks cause larger resistance in reaming it in tripping-out since the strength of dolomite rocks is larger than that of limestone. Based on our findings, use of reamers on bit is found to be the better solution to improve the tripping-out performance in the problematic geologic layers instead of conventional operational attempts such as spotting of acid and use of high viscous fluids in hole cleaning. In addition, optimization of the design and position of reamers and stabilizers is essential to succeed in the future 10,000 ft long extended-reach wells in the studied oil field.


2015 ◽  
Author(s):  
Philippe Al Khoury ◽  
Amit Kumar Sinha ◽  
Abdel Ghani Gueddoud ◽  
Amr Mohamed Serry

2021 ◽  
Vol 73 (06) ◽  
pp. 58-59
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203226, “First Multistage Fracturing of Horizontal Well Drilled in a Conventional Tight Carbonate Reservoir in an Onshore Field in the UAE: Challenges and Lessons Learned,” by Muhammad Aftab, SPE, Noor Talib, and Maad Subaihi, ADNOC, et al., prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed. The reservoir upon which this case study is focused is a tight, low-permeability carbonate reservoir with thin layers. The objective of the field case was to increase and sustain productivity of a pilot well consisting of an openhole completion. The complete paper summarizes the design processes, selection criteria, challenges, and lessons learned during design and execution phases. The study may provide a potential approach for selecting the proper hydraulic fracturing method and technique in similar cases. Introduction Reservoir X is divided into six layers. Layers X-3 through X-6 have reasonable porosity development; valid pressure points exist in X-3 and X-6. Pumpout was performed while collecting samples from X-3 and X-6, followed by short buildups. Production-logging-tool measurement was performed and found two major oil-producing layers across X-3 (60% of total production) and X-6 (40% of total production). The remaining intervals of the perforation were almost inactive. Petrophyscial and testing results of vertical Well A resulted in a decision to drill a horizontal oil producer (Well B) through Layer X-3. Well B was steered with a 2,220-ft horizontal length, out of which 1,930 ft was inside X-3 and 290 ft were above X-3 be-cause of a fault throw of 16 ft true vertical depth. The well was steered with a horizontal length of 2,080 ft in X-6. Well B was completed with a 3½-in. completion and horizontal section as an openhole. Matrix stimulation using coiled tubing was performed with 15% hydrochloric acid in Well B. The well ceased to flow after 2 weeks of declining production. Rapid pressure depletion was observed in Well B. Localized depletion around the wellbore was anticipated because of poor matrix/matrix connectivity. After comprehensive studies and risk assessments, the decision was made to recomplete Well B with a cemented fracturing string to perform hydraulic fracturing with the plug-and-perf technique. This technique will allow flexibility of stage count and stage spacing and a multi-cluster design to maximize the stimulated reservoir volume (SRV) along the upper, middle, and lower layers. In addition, the operator and service provider collaborated to enhance this design through a zero-overflush technique with diverting agents. The complete paper provides a detailed discussion of the core measurement and 1D mechanical Earth model used in the hydraulic fracturing design. Hydraulic Fracturing Design The main challenge in fracturing Well B was to ensure that the fracture generated is contained within the reservoir. Well B is completed in two layers (X-3 and X-6). The bottom part of the well is in X-6 and close to another underlying reservoir (Fig. 1).


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