Deep Directional Electromagnetic Technique Improves Well-Drilling Efficiency

2021 ◽  
Vol 73 (10) ◽  
pp. 51-52
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202265, “Leap of Faith From Conventional to EM Look-Ahead: A Game-Changing Technology To Improve Well Efficiency,” by Muhamad Yanuar Mahardi, Hendarsyah Hendarsyah, and Kharisma Endarmoyo, PT Pertamina, et al., prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. The structure in the Matindok block in Central Sulawesi operated by Pertamina has proven producible gas reserves in the Minahaki formation. One of the main challenges in this area is the low resolution of seismic data, leading to a high depth uncertainty. The complete paper describes a technology developed to meet these challenges with the capability to map and detect lithology changes ahead of the bit in real time. Geological Background A first exploration well, PEP-001, was drilled in 2018. The structure has a Miocene carbonate buildup play, and the target reservoir is the M pinnacle carbonate reef. The PEP-001 well was planned to set the 9⅝-in. casing point above the top of the M formation. Offset wells did not show any clear markers in the thick shale above the M formation that could have been used for log correlation. In previously drilled offset wells, correlation was performed convention-ally by examination of cutting samples and on drilling breaks. However, when Well PEP-001 was drilled, no apparent drilling break was observed. By the time cuttings reached the surface, the bit had drilled into 20 m of the M formation. Because the casing covered most of the upper carbonate formation, openhole logging and well-testing data were not acquired to delineate the target formation optimally. The second exploration well, PEP-002, was planned with an objective of setting 9⅝-in. casing approximately 5 m above the top of M to acquire full-interval coverage of coring, openhole wireline logging, and well testing. This information was critical for optimal reservoir delineation to allow for accurate reserves calculation and future development. Conventional correlation methods have proven insufficient for casing point placement. The presence of limestone stringers in offset wells within proximity of the top of M presented an additional challenge. The stringers could have been misinterpreted as the main carbonate body, if interpretation were based solely on cutting samples. Real-Time Electromagnetic (EM) Look-Ahead Technology

Author(s):  
Hadi Belhaj ◽  
M. S. Zaman ◽  
Terry Lay

Petrel, Eclipse and Monte Carlo are three simulators often used separately to evaluate reservoir structure, production performance and economics/planning/risk analysis respectively. Integration of the three packages provides a very comprehensive and efficient assessment tool for oilfields or blocks with limited data by avoiding incompatibility, data transformation and interface problems. Many oil and gas fields that have been discovered in the past and abandoned as a high risk venture have become of prime interest to numerous smart investors taking advantage of high oil prices and advanced technology. Some of these discoveries have exhibited reasonable hydrocarbon accumulations through seismic surveys, actual drilling and initial well-testing. Their development has previously been hindered by uncertainty and by low oil prices. The ALT Field, North Africa, is a typical example. Only nine vertical wells were drilled in the ALT Field during the 1960’s including three dry holes. Low production from three zones of Chalk Carbonate formation with moderate porosity and very low permeability (less than 1 md), meant the field has been abandoned for over three decades. Recently, with oil prices flourishing, the field has caught the eye of many potential developers. By utilizing the three-simulator approach, the ALT field has been verified as a potential producer of commercial oil. Two scenarios, single-pool and two-pool, have been established for describing the field structure, both are economically feasible, with more profitability foreseen from the single-pool scenario. The two-pool scenario demonstrated the field contains 885MMblls OIIP with estimated total reserves of 310MMbbls of oil using waterflooding alone and an additional 89MMbbls using CO2 injection. The existing six vertical producers are recommended to be used for injection, while a pattern of horizontal wells are suggested to be drilled and used as producers. The horizontal wells are favored over vertical ones to overcome the very low permeability situation. Development of the ALT Field is ongoing based upon the findings of this study. The idea of the three-simulator approach has proven workable, thus has potential to be used in similar cases once minor technical software problems are resolved.


2015 ◽  
Author(s):  
Ramzi Miyajan ◽  
Musab Khudiri ◽  
Ali Wuhaimed ◽  
Harmohan Gill ◽  
AbdulHakim Nahdi ◽  
...  

2021 ◽  
Author(s):  
Muhammad Waqas ◽  
Abdulla Saad Alkobaisi ◽  
Ashraf Yahia ◽  
William H Borland ◽  
Muhammad Atif Nawaz

Abstract An exploration well offshore UAE, which was the first of it's kind, was planned to be drilled from an island and within salt dome. Well planning was based on a structural model that was estimated using coarse 2D surface seismic (with no line crossing planned well location) and gravity measurements. This model, therefore, had a large uncertainty as to the salt location and geometry. Concerns of potential drilling hazards associated with salt required utilizing the ability of borehole seismic to look-ahead of bit to image salt and direct the well such that it would be sufficiently far away from salt face. Pre-job survey planning was first made assuming salt face to the northwest (based on gravity data) of wellhead and that the well would remain outside the salt. To ensure the well remains close, but not too close, Vertical Seismic Profile (VSP) was planned to include Salt Proximity Survey. Just prior to spudding, a surface core indicated salt was, in fact, southeast of wellhead, thus changing the objectives of VSP from locating how far away the well was from salt, to how soon will it exit salt. After survey modeling for four possible scenarios, Look-ahead Zero-Offset and Offset VSPs were acquired using vibroseis at the island, at each of four casing points and rapidly processed to guide drilling next sections. In the 26" section, the well started drilling in salt and there was concern that there would be problems with casing design if the well did not exit salt before 4000 ft. A Zero-Offset and Offset VSP were shot for reflection imaging off the salt face. The survey indicated the salt face was approaching the well but at low rate (due to dip) to ensure an exit before 4000 ft. The well was deviated southeast and it exited the salt at 3620 ft. In the 17.5" section, a second run of Zero-Offset and Offset VSP were acquired indicating the salt face was still moving away from the well toward the northwest. In the 12.25" section, a third set of Zero-Offset and Offset VSP was shot. This survey confirmed the salt face was moving continually northwest and it was suggested the well deviate northwest to remain closer to salt. A large reverse fault was also clearly imaged and confirmed by drilling. In the 8.5" section, the well was drilled northwest at high angle as could be tolerated until it was TDed below target formation "A". The final set of Zero-Offset and Offset VSP results showed the salt was, at the level of formation "A", farther northwest than could be imaged by these VSP. There has been little to no experience of drilling salt dome islands in Abu Dhabi. This paper demonstrated how look-ahead VSP guided exploration well drilling in the salt dome island. Out-of-the-box survey design and rapid turnaround processing successfully aided in imaging location of the salt face and allowed casing points to be made without having to plug back and sidetrack. Once out of the salt, VSP allowed the well to be drilled closer to salt without re-entering it.


2021 ◽  
Vol 73 (10) ◽  
pp. 46-48
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202353, “Drilling-Performance and Risk-Management Optimization Offshore Australia: Improving Overall Safety and Efficiency of the Well-Construction Process,” by Chandrasekhar Kirthi Singam, Farshid Hafezi, and Clyde Rebello, Schlumberger, et al., prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. The emergence of real-time well construction performance-monitoring centers has improved the service delivery for operators across numerous offshore oil fields in Australia significantly. The complete paper details new technologies and work flows implemented for three Australian offshore wells, with the primary objective of improving drilling efficiency while managing associated risks. Additional objectives included optimizing daily operational performance, thus delivering time savings for the operator and highlighting areas of possible improvements. Introduction The paper describes a successful drilling campaign in a challenging field in the Timor Sea. It describes how data analysis, risk evaluation, and real-time performance monitoring can be influential in saving rig time and project success. As part of this project, a major operator in Australia decided to perform an infill drilling campaign involving three high-angle directional wells (J type) in a saturated, complex field. The campaign design stage was initiated in 2017 with a main objective of delivering the project within authority-for-expenditure (AFE) budget and with planning for all potential challenges. Technical Overview The technical solution (Fig. 1) was deployed using drilling-interpretation software and executed its work flows to achieve the required objectives.


2017 ◽  
pp. 41-47
Author(s):  
E. A. Andaeva ◽  
A. V. Lysenkov ◽  
M. T. Khannanov

To increase the efficiency of hydrodynamic well testing after the geological and technical measures, it is proposed to record the pressure change at the bottom of the well during the development by means of the GIC. Such a solution will allow to combine the process of well development after the IPF with the study, thereby increasing the control over the success of the repairs carried out without additional downtime in real time.


2021 ◽  
Vol 1064 (1) ◽  
pp. 012059
Author(s):  
R R Gazizov ◽  
A P Chizhov ◽  
V E Andreev ◽  
A V Chibisov ◽  
V V Mukhametshin ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4865
Author(s):  
Kinzo Kishida ◽  
Artur Guzik ◽  
Ken’ichi Nishiguchi ◽  
Che-Hsien Li ◽  
Daiji Azuma ◽  
...  

Distributed acoustic sensing (DAS) in optical fibers detect dynamic strains or sound waves by measuring the phase or amplitude changes of the scattered light. This contrasts with other distributed (and more conventional) methods, such as distributed temperature (DTS) or strain (DSS), which measure quasi-static physical quantities, such as intensity spectrum of the scattered light. DAS is attracting considerable attention as it complements the conventional distributed measurements. To implement DAS in commercial applications, it is necessary to ensure a sufficiently high signal-noise ratio (SNR) for scattered light detection, suppress its deterioration along the sensing fiber, achieve lower noise floor for weak signals and, moreover, perform high-speed processing within milliseconds (or sometimes even less). In this paper, we present a new, real-time DAS, realized by using the time gated digital-optical frequency domain reflectometry (TGD-OFDR) method, in which the chirp pulse is divided into overlapping bands and assembled after digital decoding. The developed prototype NBX-S4000 generates a chirp signal with a pulse duration of 2 μs and uses a frequency sweep of 100 MHz at a repeating frequency of up to 5 kHz. It allows one to detect sound waves at an 80 km fiber distance range with spatial resolution better than a theoretically calculated value of 2.8 m in real time. The developed prototype was tested in the field in various applications, from earthquake detection and submarine cable sensing to oil and gas industry applications. All obtained results confirmed effectiveness of the method and performance, surpassing, in conventional SM fiber, other commercially available interrogators.


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