Please enable JavaScript for this site to function properly.
OnePetro
  • Help
  • About us
  • Contact us
Menu
  • Home
  • Journals
  • Conferences
  • Log in / Register

Log in to your subscription

and
Advanced search Show search help
  • Full text
  • Author
  • Company/Institution
  • Publisher
  • Journal
  • Conference
Boolean operators
This OR that
This AND that
This NOT that
Must include "This" and "That"
This That
Must not include "That"
This -That
"This" is optional
This +That
Exact phrase "This That"
"This That"
Grouping
(this AND that) OR (that AND other)
Specifying fields
publisher:"Publisher Name"
author:(Smith OR Jones)

Updating the Geomechanical Model and Calibrating Pore Pressure From 3D Seismic Using Data from the Gnu-1 Well, Dampier Sub-basin, Australia

Authors
Adrian White (Geo Mechanics International) | Brett McIntyre (Apache Energy) | David Castillo (GeoMechanics International) | Julie Trotta (GeoMechanics International) | Marian Magee (GeoMechanics International) | Christopher D. Ward (GeoMechanics International) | Paul O'Shea (Apache Energy)
DOI
https://doi.org/10.2118/110926-PA
Document ID
SPE-110926-PA
Publisher
Society of Petroleum Engineers
Source
SPE Reservoir Evaluation & Engineering
Volume
12
Issue
03
Publication Date
June 2009
Document Type
Journal Paper
Pages
408 - 418
Language
English
ISSN
1094-6470
Copyright
2009. Society of Petroleum Engineers
Downloads
3 in the last 30 days
846 since 2007
Show more detail
View rights & permissions
SPE Member Price: USD 10.00
SPE Non-Member Price: USD 30.00

Summary

A post-mortem analysis of the Gnu-1 well was conducted to help us to understand drilling experiences in the context of the pore-pressure and stress profiles. The post-mortem involved a review of the drilling experiences and an analysis of CAST image data, wireline-log data, and the logging-while-drilling (LWD) logs. This information was used to refine and verify a geomechanical model (in-situ stress, pore pressure, and rock-mechanical properties) in the vicinity of the Gnu-1 well. Of prime concern was the verification of the predrill pore-pressure prediction previously undertaken using 3D-seismic-velocity data and offset-well data. Wellbore-failure and natural-fracture analyses were integral parts of the post-mortem. Wellbore breakouts seen in the image data allowed the pore pressure in the 8.5-in. hole section of Well Gnu-1 to be constrained. Modeling using image data collected in the Athol formation indicates that the pore pressure does not increase as rapidly as was estimated in the predrill study. Pore pressures in the North Rankin formation and below were consistent with the predrill study. The geomechanical model was able to explain the losses seen in the Athol formation in Well Gnu-1 when using the mud weights experienced by the open hole at the time of drilling.

Introduction

The Gnu prospect is situated in the northern portion of Block WA-209-P in the Dampier subbasin, Australian northwest shelf (Fig. 1). The prospect is located within the Reindeer gas field. A number of offset wells exist in the region, the closest wells being Well Reindeer-1 (approximately 1.5 km to the northeast) and Well Caribou-1 (2 km to the southeast).

Well Gnu-1 was designed as an exploration well. The anticipated overburden stratigraphy at the location of Well Gnu-1 consists of Tertiary and Upper Cretaceous carbonates, marls and siltstones that overlie Cretaceous claystones, siltstones and minor sandstones, and greensands. The primary aim was to drill vertically to intersect the Muderongia australis glauconitic sandstone and then to build angle and continue drilling a deviated hole through the main Reindeer field gas appraisal within the Legendre formation and into the North Rankin, Brigadier, and Mungaroo formations.

File Size  2 MBNumber of Pages   11

References

Aadnøy, B. and Bell, J.S. 1998. Classification of drilling-induced fracturesand their relationship to in-situ stress direction. The Log Analyst39: 27-42.

Barton, C.A., Zoback, M.D., and Moos, D. 1995. Fluid flow along potentially active faults in crystalline rock.Geology 23 (8): 683-686.doi:10.1130/0091-7613(1995)023<0683:FFAPAF>2.3.CO;2.

Bell, J.S. 1990. Investigating stressregimes in sedimentary basins using information from oil industry wireline logsand drilling records. Geological Society, London, SpecialPublications 48: 305-325. doi:10.1144/GSL.SP.1990.048.01.26.

Ewy, R.T. 1999. Wellbore-Stability Predictions by Useof a Modified Lade Criterion. SPE Drill & Compl 14(2): 85-91. SPE-56862-PA. doi: 10.2118/56862-PA.

Hermanrud, C., Wensaas, L., Teige, G.M.G., Nordgård-Bolås, H.M., Hansen, S.,and Vik, E. 1998. Shale porosities from well logs on Haltenbanken (offshoremid-Norway) show no influence of overpressuring. In Abnormal Pressures inHydrocarbon Environments, ed B.E. Law, G.F. Ulmishek, and V.I. Slavin,65-68. Tulsa: AAPG Memoir 70, AAPG Publications.

Hillis, R.R. and Williams, A.F. 1993. The contemporary stress field of theBarrow-Dampier Sub-Basin and its implications for horizontal drilling.Exploration Geophysics 24 (4): 567-576.doi:10.1071/EG993567.

Horsrud, P. 2001. EstimatingMechanical Properties of Shale From Empirical Correlations. SPE Drill& Compl 16 (2): 68-73. SPE-56017-PA. doi:10.2118/56017-PA.

McNally, G.H. 1987. Estimation of coalmeasures rock strength using sonic and neutron logs. Geoexploration24 (4-5): 381-395. doi:10.1016/0016-7142(87)90008-1.

Mouchet, J.P. and Mitchell, A. 1989. Abnormal Pressures While Drilling:Origins, Prediction, Detection, Evaluation. Paris: Elf EP-Editions,Editions Technip.

Osborne, M.J. and Swarbrick, R.E. 1997. Mechanisms for generatingoverpressure in sedimentary basins: a re-evaluation. AAPG Bulletin81 (6): 1023-1041.

Plumb, R.A. and Hickman, S.H. 1985. Stress-induced boreholeelongation: A comparison between the four-arm dipmeter and the boreholeteleviewer in the Auburn geothermal well. J. of Geophysical Research90 (B7): 5513-5521. doi:10.1029/JB090iB07p05513.

van Ruth, P., Hillis, R., and Tingate, P. 2004. The origin of overpressure inthe Carnarvon Basin, Western Australia: implications for pore pressureprediction. Petroleum Geoscience 10 (3): 247-257.doi:10.1144/1354-079302-562.

Ward, C.D., Mujica, D., and Ferrebus, C. 2003. Constraining Pore Pressurefrom Wellbore Failure Observations: examples from Venezuela. Presented at theAAPG International Conference, Barcelona, Spain, 21-24 September.

Zoback, M.D. 2007. Reservoir Geomechanics, 464. Cambridge, UK:Cambridge University Press.

Zoback, M.D. and Healy, J. 1984. Friction, faulting and in-situ stress.Annales Geophysicae 2: 689-698.

Zoback, M.D., Moos, D., Mastin, L., and Anderson, R.N. 1985. Well bore breakouts andin-situ stress. J. of Geophysical Research 90 (B7):5523-5530. doi:10.1029/JB090iB07p05523.

    • Issue Preprint
    • Issue 01
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
    • Issue 06
    • Issue 05
    • Issue 04
    • Issue 03
    • Issue 02
    • Issue 01
Show more

Other Resources

Looking for more? 

Some of the OnePetro partner societies have developed subject- specific wikis that may help.


 


PetroWiki was initially created from the seven volume  Petroleum Engineering Handbook (PEH) published by the  Society of Petroleum Engineers (SPE).








The SEG Wiki is a useful collection of information for working geophysicists, educators, and students in the field of geophysics. The initial content has been derived from : Robert E. Sheriff's Encyclopedic Dictionary of Applied Geophysics, fourth edition.

  • Home
  • Journals
  • Conferences
  • Copyright © SPE All rights reserved
  • About us
  • Contact us
  • Help
  • Terms of use
  • Publishers
  • Content Coverage
  • Privacy
  Administration log in