Technologies for pretest around circumference of wellbore at the identical depth using a new formation tester

XiaoDong CHU, Lin HUANG, TieMin LIU, QiYong JIA, YongZeng XUE, YongChao CHEN, YouXiang ZUO

Prog Geophy ›› 2026, Vol. 41 ›› Issue (4) : 1864-1875.

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Prog Geophy ›› 2026, Vol. 41 ›› Issue (4) : 1864-1875. DOI: 10.6038/pg2026JJ0242

Technologies for pretest around circumference of wellbore at the identical depth using a new formation tester

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Abstract

This study aims to address key limitations of traditional formation testers in complex reservoir evaluation, specifically the inability to perform multi-azimuth pretests at a single depth for in-situ anisotropy characterization, and the lack of an efficient recovery mechanism after probe seal failures. To bridge these gaps, a novel integrated formation tester (EFDT-Union) was developed, which enables pretesting, fluid sampling, and site-wall coring in a single downhole run. The core innovation lies in a newly designed adapter module enabling a "dynamic probe rotation-stationary tool anchoring" mechanism. This allows the probe module to rotate freely by 0°~360° circumferentially while the main tool body remains azimuthally fixed, representing a pioneering technology nationally and internationally. To underpin the data interpretation workflow for this tool, an analytical solution for circular-probe pressure diffusion equations incorporating anisotropic probe coefficient formulas was established and validated with numerical simulations. A combined mobility estimation strategy synergizing the drawdown method (based on steady-state flow principles) and the buildup method (utilizing pressure transient analysis) was proposed. The buildup method employs derivatives of pressure with respect to specific time functions (characterized by slopes: -0.5 for spherical flow, 0 for radial flow) to identify flow regimes and employs linear regression to extrapolate formation pressure. Validation results confirmed high consistency between analytical and numerical solutions with pressure derivative deviations less than 5% during spherical and radial flow regimes. Field applications at an oilfield in the South China Sea successfully demonstrated: (1) Multi-azimuth pretesting at identical depths (e.g., at depth of 3370.3 m, a mobility ratio of approximately 1.67 between azimuths 172° and 350° was observed, providing direct evidence of near-wellbore in-situ permeability anisotropy). (2) The capability for rapid probe reorientation and resealing post-seal failure (e.g., a successful 89° rotation followed by a pretest at depth of 3369.9 m after an initial seal failure at 350°), ensuring complete data acquisition efficiently. Pressure transient analysis (PTA) at these depths illustrated significantly different spherical flow development times and mobilities between azimuths (e.g., ~301.6% mobility difference at 3370.3 m). Importantly, formation pressure values derived from drawdown and buildup methods are in very good agreement at the identical depth with average absolute errors less than 0.007 MPa (specifically 0.0069 and 0.0015 MPa in the field application), and mobility values derived from drawdown and buildup methods exhibited order-of-magnitude consistency with relative errors less than 31% (specifically 7.0%, 28.9%, and 30.8% in the field application), jointly corroborating the reliability of the interpretation methodology and the effectiveness of the tool design. In conclusion, the EFDT-Union system equipped with its novel probe rotation mechanism and its integrated interpretation methodology, significantly enhances pretest efficiency and data integrity in complex heterogeneous reservoirs through multi-azimuth testing at identical depths and relocation-enabled probe resealing at matching depths following initial seal failures, thereby effectively mitigating operational risks and reducing costs.

Key words

Formation tester / Pretest / Anisotropy evaluation / Pressure diffusion equations / Probe coefficients / Pressure drawdown and buildup analyses

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XiaoDong CHU , Lin HUANG , TieMin LIU , et al . Technologies for pretest around circumference of wellbore at the identical depth using a new formation tester[J]. Progress in Geophysics. 2026, 41(4): 1864-1875 https://doi.org/10.6038/pg2026JJ0242

References

Biryukov D , Kuchuk F . Pressure transient and steady-state solutions for pressure diffusion mixed boundary value problems in porous media. Far East Journal of Applied Mathematics, 2010, 48 (2): 75- 126.
Biryukov D , Kuchuk F J . Pressure transient solutions to mixed boundary value problems for partially open wellbore geometries in porous media. Journal of Petroleum Science and Engineering, 2012, 96-97: 162- 175.
Bourdet D , Ayoub J A , Plrard Y M . Use of pressure derivative in well-test interpretation. SPE Formation Evaluation, 1989, 4 (2): 293- 302.
Chen H Q , Cheng S X . Application of artificial intelligence technology in detailed reservoir description. Progress in Geophysics, 2025, 40 (4): 1717- 1731.
Chen Y C, Zuo Y X, Yuan C X, et al. 2023. Development and application of new constant differential pressure pump module for formation tester. //2023 International Field Exploration and Development Conference (in Chinese). Wuhan, 20-22.
Dussan V E B . A robust method for calculating formation mobility with a formation tester. SPE Reservoir Evaluation & Engineering, 2011, 14 (2): 239- 247.
Feng Y R , Zuo Y X , Wang J , et al. Advances and challenges in formation test and practical application. Well Logging Technology, 2019, 43 (3): 217- 227.
Feng Y R , Zuo Y X , Zhou M G , et al. Principle and applications of slug flow formation in formation testers. Well Logging Technology, 2020, 44 (6): 557- 564.
Goode P A , Thambynayagam R K M . Permeability determination with a multiprobe formation tester. SPE Formation Evaluation, 1992, 7 (4): 297- 303.
Kuchuk F J , Ramakrishnan T S , Onur M . Wireline Formation Testing: Hardware, Pressure Transient Testing, Interpretation and Sampling. Richardson: Society of Petroleum Engineers, 2021
Menon S, Alameri K, Nasr K K, et al. 2025. Unprecedented sampling efficiency in low resistivity pay with ORA intelligent wireline formation testing platform for ADNOC offshore. //ADIPEC. Abu Dhabi: SPE, doi: 10.2118/229729-MS.
Moran J H , Finklea E E . Theoretical analysis of pressure phenomena associated with the wireline formation tester. Journal of Petroleum Technology, 1962, 14 (8): 899- 908.
Qin X F , Feng Y R . Research on the setting function of dual packer on formation tester. Hydraulics Pneumatics & Seals, 2012, 32 (12): 12- 13. 12-13, 17
Schlumberger . Fundamentals of Formation Testing. Sugar Land: Schlumberger, 2006
Wilkinson D , Hammond P S . A perturbation method for mixed boundary-value problems in pressure transient testing. Transport in Porous Media, 1990, 5 (6): 609- 636.
Zhou M G , Liu S M , Feng Y R , et al. Research on formation characteristic tool and its application. Well Logging Technology, 2008, 32 (1): 72- 75.
Zhou M G , Zuo Y X , Xue Y Z . Novel sampling systems of 3D radial adaptive setting probes. Progress in Geophysics, 2022, 37 (2): 938- 944.
Zuo Y X , Feng Y R , Lu F W , et al. New downhole fluid spectrometer for composition analysis of downhole fluids. Well Logging Technology, 2021, 45 (2): 128- 133.
欢庆 , 顺新 . 精细油藏描述中的人工智能技术及其应用. 地球物理学进展, 2025, 40 (4): 1717- 1731.
陈永超, 左有祥, 原旭晟, 等. 2023. EFDT新型等压差泵抽模块研制及应用. //2023油气田勘探与开发国际会议. 武汉, 20-22.
永仁 , 有祥 , , 等. 地层测试技术及其应用的进展与挑战. 测井技术, 2019, 43 (3): 217- 227.
永仁 , 有祥 , 明高 , 等. 地层测试仪中段塞流的形成原理及应用. 测井技术, 2020, 44 (6): 557- 564.
小飞 , 永仁 . 地层测试器双封隔器坐封性能研究. 液压气动与密封, 2012, 32 (12): 12- 13. 12-13, 17
明高 , 书民 , 永仁 , 等. 钻井中途油气层测试仪(FCT)研究进展及其应用. 测井技术, 2008, 32 (1): 72- 75.
明高 , 有祥 , 永增 . 新型3D推靠自适应坐封取样系统的研发与应用. 地球物理学进展, 2022, 37 (2): 938- 944.
有祥 , 永仁 , 法伟 , 等. 新型井下流体光谱组成分析技术. 测井技术, 2021, 45 (2): 128- 133.

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