Application of proper technologies in the heavy and extra-heavy oil field of the Orinoco Oil Belt of Venezuela has led to significant improvements in oil production during the last 30 years. However, the many cold production methods tested in the area have achieved a maximum recovery of only 20%. Increasing the recovery factor remains a priority for the oil industry and has led to the testing of hot production methods, such as steam-assisted gravity drainage (SAGD). SAGD uses two parallel horizontal wells, one drilled above the other, with continuous steam injection to achieve recovery efficiencies up to 60% in many heavy and extra-heavy oil fields worldwide. Magnetic ranging technologies are used to maintain precise separation along the trajectory of the two wells, which is critical for the effectiveness of SAGD technique. If the horizontal wells are too close, the steam will rapidly migrate to the production well. If there is excessive separation, gravity drainage will not occur. A national Venezuelan operator determined that SAGD technology is applicable in the San Tome area of the Orinoco heavy-oil Belt and proposed to drill a pair of SAGD wells in the U1, 3 MFB-53 reservoirs to evaluate the effectiveness of the technology to recover an additional 2 MMBB. Increasing the recovery factor to 38% in the area affected by injection with a rate of 1,500 BNPD and holding it for 3 years will determine the success of the technique in the Orinoco Oil Belt. This publication will describe the characteristics and production history of the Bare Reservoir, as well as the implementation of SAGD drilling techniques in the development of related fields. Specifically addressed will be how the precise pre-planning and execution of the separation and alignment between the two existing wells was achieved using active magnetic-ranging technology. Finally, production results will be presented and explained.
This paper has the recommended procedures to be carried out in each phase: Surface, Intermediate I and II, horizontal and completion with frac string, for Unconventional Appraisal HP/HT wells across Deyab formations in Abu Dhabi (UAE), as well as the technology to be used and avoid, to drill the wells saving time and money helping to make a rentable project. Due to the information received of the zone was scarce, in addition the first well in the area (offset well and taken as a reference) had many operational problems. The operations during drilling the next three wells in PAD # 1 were recorded, analyzed and optimized, resulting in a learning catalog for the area, saving a considered quantity of rig days with a huge impact in the budget and the most important, the exposure of the crews/people at the location was minimized to this hazard environment. The PAD# 1 has 03 horizontal wells, the design is Heavy Casing Design, where each phase has its characteristics to be drilled and cased. The reservoir consists of 03 cl early identified formations: Jubaila, Hanifa and Tuwaiq Mountain into the range from ± 12330 ft. TVD to ± 12900 ft. TVD. Reaching the targets with horizontal wells from 16,000 ft. MD to 17,500 ft. MD. After analyzing each section and getting the recommendations from different service companies and specialist, the changes were implemented in the next well regarding drilling fluid MW, BHA's design, bit type & design, wiper trips, slurries, trajectories, etc. taking as result drilling wells more complicate d without operational issues, in deepest formation, drilling more than 1000 ft. MD and 600 ft. TVD, and saving 3.25 MM$ and 15.2 days per well The PAD # 1 in Deyab field, is the pioneer for the initial development of fracking in UAE. There hasn't had a drilling procedure in detail to reach the target without having issues. This new concession has been already of interest to be developed in conjunction with the National Company, so create a Drilling Learning Catalogue as add value at the moment to handover the wells is a must.
To meet the current oil and gas market challenges, there is an industry need to optimize cost by safely drilling longer horizontal wells to maximize well productivity. Drilling challenges include the highly deviated trajectory that starts from the surface sections and wellhead, the high DogLeg Sevirity (DLS) profile with collision risks, and the thin complex geological structures, especially in new unconventional fields where numerous geological and geomechanical uncertainties are present. To mitigate for those challenges, reviewing the existing drilling techniques and technologies is necessary. To compete in the current Hi-Tech and Automation era, the main challenges for directional drilling service providers are to reduce well time, place wells accurately, and improve reliability, reducing repair and maintenance costs and helping the customer reduce time and costs for the overall project. Offset wells analysis and risk assessments allowed identifying the main challenges and problems during directional drilling phases, which were highlighted and summarized. As a proposed solution, the new generation of intelligent fully rotating high dogleg push-the-bit rotary steerable system has been implemented in the UAE onshore oil and gas fields to improve the directional drilling control and the performance. This implementation reduced the Non-Productive time (NPT) related to the human errors as the fully automation capabilities were being utilized. The new rotary steerable system has the highest mechanical specs in the market including self-diagnosis and self-prognosis through digital electronics and sophisticated algorithms that monitor equipment health in real-time and allow for managing the tool remotely. As a result, the new intelligent RSS was implemented in all possible complex wellbore conditions, such as wells with high DLS profile, drilling vertical, curve, and lateral sections in a single trip with high mud weight and high solid contents. Automation cruise control gave the opportunity to eliminate any well profile issues and maintain the aggressive drilling parameters. Using the Precise Near-bit Inclination and Azimuth and the At-Bit Gamma real-time data and high-frequency tool face measurements in the landing intervals where required for precise positional control to enable entering the reservoir in the correct location and with the correct attitude helping the customer's Geology and Geophysics department to place wells accurately while maintaining a high on bottom ROP.
A PDC design containing updated fracturing elements and utilizing in-bit sensing to optimize parameters can deliver improved ROP and drill a challenging heterogeneous section containing massive chert in one run compared to previously used PDC. The demonstration is supported by a real field case from an unconventional gas exploratory field project in Abu Dhabi. In this unconventional field, seven wells have been drilled using three bits on average to complete the 12 ¼″ section (tricone and PDC) where the presence of chert has resulted in additional trips due to bit life. The content of cherts are large, at approximately 2,000 ft thick, which is the reason why it was decided to think of a new customized PDC bit design and use it in well number seven. The plan is to prove that is possible to achieve one run to TD by fracturing cutter development and optimized drillers roadmap using in-bit sensing. The new unique PDC shaped cutter, with increased point surface area and thicker diamond table, makes the overall design more impact resistant and reduces vibrations while drilling. In bit sensing data is utilized to increase the efficiency in rock interaction through optimized parameters. It will be used in the ongoing exploratory project to demonstrate its advantage in terms of cost saving and rig time reduction. The study will compare the data with previously used bit and create a basement for the exploratory field in 12 ¼″ section. A strong hypothesis is that this bit will complete the well in this particular area and optimize drilling costs in development studies. Where such non-homogenous formations containing massive cherts can be crossed and have detrimental impact on the bit life, the novelty is to bring to the stage an enhanced combined PDC and parameter solution, which will be able to offer a different alternative by reducing torque, having healthier wells, and optimizing drilling cost in this unconventional field where drilling CAPEX reduction are paramount.
The understanding of salt beds has been significantly improved over the years; however, certain operational challenges still persist. Conditions encountered during drilling salt formations may lead to stuck Logging While Drilling (LWD) and or wireline tools, which, at times, can contain radioactive sources. As data gathering remains a primary requirement in exploration wells, cost optimization, beside risk mitigation, is a further challenge in today’s economic landscape. A holistic approach is proposed to address these main objectives. The conventional procedure required drilling and formation evaluation (LWD and or wireline) in the section above the interbedded salt formation, followed by rotary steerable (RSS) only in the interbedded salt formation sections of the well. Considering the shallow depths of the well and the proximity to the aquifers, the threat posed by losing radioactive sources in the well is significant, therefore, formation density and neutron porosity logging operation is often compromised due the inherent risk. Logging While Tripping, a method in which tools record open hole data from inside the pipe, resolves this compromise, as the risk of lost in hole (LIH) is virtually eliminated. The empty LWT collars are run in the last bit trip or reamer run, as they do not affect the drilling operation. Once the well’s total depth is reached, the LWT logging tools are pumped from surface, safely inside of the pipe, and data is acquired while tripping the drill pipe out of the well. If the situation is evaluated as risky, drilling operation may continue without data acquisition. In case the logging tools already were deployed, they can be retrieved at any time by wireline or slickline. Prior to the introduction of the LWT in the drilling/data acquisition procedure, only gamma ray - sonic data was acquired over the challenging formation sections. Compressional and shear data may be important to improve modelling accuracy; however, they may be negatively affected by various factors such as drilling noise, mud properties, washouts and gas in the formation, particularly reservoir rocks interbedded with thick salt beds. When compared to the Neutron-Density porosity, sonic porosity is noticeably inferior, showing limited formation signature. Neutron-Density porosity correlates well with core data.
The proposal of this paper is to share the knowledge learned in this new procedure and techniques implemented in HP/HT Unconventional wells, created by the Unconventional (UC) Drilling Department at Abu Dhabi which involve around ten different services, where each has a high importance and contribution for the collective success of the well at the moment to frac and hence the feasibility of the project. In order to assure the integrity and accessibility of the Frac String during Plug and Perf hydraulic fracturing operations of one of the toughest rock in Unconventional business worldwide, one procedure has been developed for running operations best practices. Pressure testing the Frac String (FS) during running in hole in stages while in vertical section to sure safe and successful Wireline setting and retrieving nipples plug with more than 30% solids in the system (high mud weight) to guarantee no leak in the string prior reaching total depth (TD). Hanging and testing cross over (XO), assuring compatibility with the wellhead connections. Cementing up to18.7 ppg. Flexible and expandable slurries, cement inside previous casing and apply pressure on surface to avoid gas percolation during the cement setting period. Cleaning out with Coiled tubing (CT) to ensure no obstruction and using different completion fluids for future accessibility. And finally, Pressure testing the Frac string up to 14ksi all are new practices and proven mitigation measures for all assessed risks for hydraulic fracturing operations. This paper is about sharing this new procedure in Abu Dhabi for having a cemented FS in UC wells High Pressure / High Temperature (HP/HT) with 100% integrity and internal accessibility to run plugs, perforations, logs and be able to apply high surface pressure to frac the tight reservoir in the planned zone, creating the desired permeability for future production.
The proposal of this paper is to share the case history and knowledge learned in this first application of the multistage zipper frac procedure and techniques in Biogenic wells. This breakthrough achievement was planned and executed by ADNOC Onshore Biogenic Drilling Department in Abu Dhabi which involves seven different services, each has a high importance and close collaboration was a key contributor to the feasibility of the project and the collective success obtained. The Zipper frac method selected and tailored by the Biogenic Team for the specific application enables to significantly increase the number of fracs per day performed over 2 wells. This technique stages multi-well completions, where wells are completed in a back-and-forth manner. One well is being pumped /fractured while the other well is being plugged and perforated for next stage. One of the key achievements in the Biogenic Zipper frac operation lies in the easy switch from line to another by using a manifold in a safe manner and without confusion. Because of the focus and high potential of Biogenic gas, Biogenic Team faced the challenge of delivering the two wells on a very tight schedule. This led the Team to review, select and implement a novel methodology that would deliver time and cost savings to the Project. New ideas were scouted and analyzed by different departments and service companies to select the most appropriate. Upon selection of the zipper frac method, meetings were done to issue and finalize a proper implementation plan for this multi-frac operation, which was a first in ADNOC Onshore. Explaining in workshops to key stakeholders and respective higher management the methodology and plan as well as the associated savings was essential to get full support and endorsement for implementing this method. There was no doubt that this method was the best way to achieve the goal with the tight given timeframe. Successful implementation resulted in of around 50 days savings compared with applying the conventional multiple frac procedure / method on a well-by-well basis. Wider application of this method represents a breakthrough in delivering future fracked wells cheaper and faster thereby bringing significant savings to future Biogenic gas development projects. Because of the importance of ongoing assessment and potential future development of Biogenic gas and unconventional resources, sharing details of ADNOC Onshore first implementation of the Zipper frac methodology is of benefit to the industry. The detailed account of its implementation (inclusive of added important technical features such as dissolvable plug and perf technology) that has delivered safely and successfully twenty-four (24) staged fracs in a short time frame represents a piece of useful knowledge.
The purpose of this paper is to share the results and knowledge learned in implementing new procedure and techniques to rotate the 5-1/2", 26 PPF, T-95/P-110 Frac String (FS) during running into Unconventional wells. Developed by ADNOC Onshore ASR - UC Drilling Department at Abu Dhabi (U.A.E.) the novelty involves six (06) different technologies necessary to minimize axial buckling in the monobore completion while maximizing well accessibility and integrity during the Rigless frac operations. The 6 key enablers technologies employed to rotate the Frac String up to 30,000 pound-ft: Connection: strength to withstand rotation required to release the axial buckling.High Speed Reamer Shoe: open hole debris cleaning / obstruction removal.Bonded Ceramic Centralizers: providing 80% standoff, reducing the friction factor and removing the mud cake with the rotation.Casing Running Tool: designed to wash down and rotate FS during running.Rotating Tubing Hanger: enabling FS rotation using different techniques and design a new mechanism for it after landed and locked into the Tubing Head Spool.Rotating Cement Head: ability to rotate the FS while pumping cement and plugs simultaneously. Because of friction, sliding during running will result in helicoidal buckling of the FS that has a negative knock down effect on later completion operations / interventions and even in some cases not possible to reach the TD. The results of previous UC wells where FS was run in sliding mode revealed issues due to the helicoidal buckling of the FS impairing annulus / cement bond quality, creating tortuosity and altering the Internal Diameter (ID) leading to issues in accessing the well bore with the Plug and Perf tool for the fracking operations. The total depth for standard UC wells ranges from 16,000’ to 23,000’ MD with ± 12,500’ TVD and ± 8000’ MD 8"1/2 horizontal section dipping up to ±92° inclination for production reasons. Such profiles generate Friction Factor (FF) ± 0.5 in Open Hole. Based on performed simulations and depending on the well profile, surface torque required to rotate the string was between 25,000 to 30,000 pound-ft. This paper will describe and provide details on how the FS helicoidal buckling was minimized and its limitations overcome thanks to the six key enablers technologies devised by Onshore ASR - UC Drilling Department. It will also highlight other important added benefits such as mud cake removal, improved annulus geometry and cement bond.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.