Landing with confidence and accuracy in a big bore subsea gas producer – an integrated approach for setting a critical casing point in the Jansz-Io field development
Leigh Thomas A , Matthew Waugh A , Matthew Thornberry A , Hanming Wang B , Haifeng Wang C D , Farshid Hafezi C , James Dolan C and Anis Ali CA Chevron Australia Pty Ltd, QV1 Building, 250 St. Georges Terrace, Perth WA 6000, Australia.
B Chevron Energy Technology Co, 1400 Smith St, Houston, TX 77002, U.S.
C Schlumberger Australia Pty Ltd, Level 5, 10 Telethon Ave, Perth WA 6000, Australia.
D Corresponding author. Email: Hwang9@slb.com
The APPEA Journal 61(1) 132-145 https://doi.org/10.1071/AJ20069
Submitted: 13 January 2021 Accepted: 3 March 2021 Published: 2 July 2021
Abstract
As part of the Gorgon Stage 2 project, a total of four production wells were installed at a new manifold within the Jansz-Io gas field. A key well construction challenge was the placement of the 12 ¼″ section total depth (TD). Due to the presence of reservoir depletion, the mud weight required to drill the sandstone would be insufficient to prevent wellbore collapse in the Barrow Shale immediately above the reservoir. Hence, the casing design called to isolate the entire Barrow Shale interval by placing the 9 ⅝″ production liner shoe immediately inside the reservoir. To avoid damaging the high-quality sandstone in the upper reservoir, it was desired to limit the reservoir penetration to less than 1 m true vertical depth (TVD) at 80° inclination. Chevron recognised several challenges in landing the wells, which included: seismic uncertainty of the reservoir top, poor resistivity contrast and the lack of significant markers in the overburden. Conventional methods such as near-bit gamma ray carried high risk because the sensor offset to bit is close to the penetration limit. Therefore, a new approach of integrating a deep directional resistivity (DDR) tool and an at-bit resistivity measurement to make the casing point decision was proposed. With this new approach, all four wells were landed, with actual reservoir penetration less than 1 m TVD. The real-time data from the DDR tool allowed the operator to efficiently drill the section, only reducing the rate of penetration immediately prior to entering the reservoir. The at-bit resistivity tool, drilling parameter changes and cuttings identification were beneficial to confirm reservoir entry and call section TD.
Keywords: Landing, logging-while-drilling, at-bit resistivity, deep directional resistivity, detection ahead of bit, 9 ⅝″ casing point setting, Greater Gorgon project, Jansz-Io gas field, Exmouth Plateau, Northern Carnarvon Basin.
Leigh Thomas is a Well Engineer at Chevron Australia and is responsible for the engineering of the Jansz-Io DC-3 wells. Thomas holds a BEng (Honours, 1st Class) in Mechanical Engineering from the University of Western Australia. He is a member of the Society of Petroleum Engineers (SPE). |
Matthew Waugh is a Petrophysicist at Chevron Australia, working in the Applied Reservoir Management Team, supporting the Gorgon and Jansz subsurface development teams. Prior to joining Chevron, he worked in various global locations supporting development and exploration activities as an Asset Petrophysicist. Matt graduated from the University of Western Australia with a BEng (Civil) in 2003 with Honours. |
Matthew Thornberry is an Operations Geologist at Chevron Australia, joining in 2011. At Chevron he has worked on various development, appraisal and exploration projects, including Gorgon Foundation, CO2 Sequestration and Gorgon Stage 2. Prior to joining Chevron, he worked as a contract Wellsite Geologist on the North West Shelf. Matt started out in the oil and gas industry as a Mudlogger after graduating from the University of Western Australia in 2004 with BSc (Coastal and Marine Geoscience) with Honours (Geology) degrees. |
Hanming Wang is a Research Scientist with Chevron Technology Center. Before his career with Chevron, he was a Research Scientist with the Schlumberger Formation Evaluation Center in Houston. His main research interests are resistivity and dielectric tools, modelling, data processing and interpretation. He has authored and co-authored more than 60 papers in the area of resistivity and dielectric logging. He was the recipient of the Distinguished Technical Achievement in Formation Evaluation award in 2014 and Best Paper of Petrophysics Journal in 2019 from the Society of Petrophysicists and Well Log Analysists SPWLA. He holds PhD in Electrical Engineering from the University of Houston. |
Haifeng Wang graduated from Peking University in China and holds two BSc degrees (Computer Science, Economics) and a MSc degree in Geology. Haifeng has 19 years of experience in the industry involving many areas, like MWD/LWD, directional drilling, geosteering and reservoir mapping, Geology and Geophysics software and project management. He current works for Schlumberger as the Geosteering and Reservoir Mapping Domain Champion for Asia and is based in Perth Australia. |
Farshid Hafezi graduated from Sharif University of Technology in 2001 with MSc in Mechanical Engineering. His working career spans 18 years in the oil and gas industry, starting as a MWD/LWD Engineer with Schlumberger then directional driller, RSS Technical Champion and Drilling Engineer in many locations, such as the Middle East, Asia and Australia. Since joining Schlumberger Australia as Senior Drilling Engineer in 2013, he has been involved in many offshore projects, including Chevron’s Wheatstone, BHP’s Pyrenees, ConocoPhillips’s Bayu-Undan and Chevron’s GS-2. Farshid is active in SPE as well as local Perth oil and gas communities, such as DrillWell and DrillSafe. |
James Dolan is a Principal Petrophysicist for Schlumberger. He holds a MSc in Geology from Victoria University of Wellington, New Zealand. Of his 20 years in the industry, 18 have been with Schlumberger, holding various positions. These positions include a Logging Engineer, Geosteering Geologist and, most currently, a Petrophysicist. James has extensive experience in both conventional and unconventional reservoirs and has held several assignments in Australasia, Scandinavia and Europe. |
Anis Ali graduated from Sana’a University in Yemen with a Bachelor’s degree in Mechanical Engineering. He is currently an Australia, New Zealand and Papua New Guinea Drilling Engineering Manager for Schlumberger Well Construction based in Perth. Anis has been working for Schlumberger Drilling and Measurements for 16 years. During these years, he was involved in a wide variety of well construction projects for clients such as Aramco, Chevron, ExxonMobil, BP, Woodside, Beach and Santos. |
References
Dong, C., Dupuis, C., Morris, C., Legendre, E., Mirto, E., Kutiev, G., Denichou, J.-M., Viandante, M., Seydoux, J., Bennett, N., Zhu, Q., and Zhong, X. (2015). Application of Automatic Stochastic Inversion for Multilayer Reservoir Mapping while Drilling Measurements. Paper presented at the Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, UAE, November 2015.Seydoux, J., Legendre, E., Mirto, E., Dupuis, C., Denichou, J.-M., Bennett, N., Kutiev, G., Kuchenbecker, M., Morriss, C., and Yang, L. (2014). Full 3D Deep Directional Resistivity Measurements Optimize Well Placement and Provide Reservoir-Scale Imaging While Drilling. Paper presented at the SPWLA 55th Annual Logging Symposium, 18–22 May, Abu Dhabi, United Arab Emirates. Society of Petrophysicists and Well-Log Analysts.
