Effects of Harsh Weather on Delayed Wireline Formation Fluid Sampling

  • X. Wang
  • G. LeiEmail author
  • N. P. Hardikar
  • R. DiFoggio
  • X. Zeng
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)


This paper discusses two cases where formation fluids were sampled after prolonged exposure to drilling fluid invasion. The long exposure occurred due to suspension of rig activities following the arrival of the Typhoon Meranti, in South China Sea. This comparison highlights the various factors influencing fluid sampling after unexpected delays. This paper attempts to answer the question, “In what ways does prolonged exposure to invasion affect formation testing and does sampling need to be cancelled due to such unforeseen delays?”

Both of these wells were ready for the formation testing operation when the typhoon arrived and caused suspension of all rig activity indefinitely. The testing started 13–16 days after drilling, once the typhoon dissipated. Representative formation oil samples were collected in both wells, but the clean-up and sampling performances were dissimilar. The formation oil breakthrough times were very different, about 6 h with pumped volumes of 120–200 l for the medium-high viscosity oil (>200 cP) and about 3 h with pumped volume of 30–50 l for the light oil (<1 cP), respectively. These results provided a good opportunity to study the influence of unexpected delays on formation testing.

Two 3-D near-wellbore reservoir models were set up using data from coring, open-hole log interpretation and laboratory PVT analysis results. Simulation runs were carried out to history match the pressure profile, pumped volume history and water cut (WBM contamination) performance. The invasion profile, which includes the flushed zone, the transition zone and the virgin zone, was studied to compare the influence of prolonged invasion on each of the cases.

Results of the study show that the influence of extended time exposure to drilling fluid invasion is limited for a light oil reservoir for which there is a small viscosity difference between formation oil and the WBM filtrate. By contrast, medium-high viscosity oil with its deeper flushed zone required longer WBM filtrate clean-up. The observations provide a useful background for pre-job modelling and post-job analysis of formation testing jobs.


Formation testing Prolonged water-based mud filtrate invasion 3-D near-wellbore modelling Viscosity ratio Copyright 2017 Shaanxi petroleum society 



The authors would like to thank China National Offshore Oil Company (CNOOC) for permission to use the data and Baker Hughes for the permission to present this paper.


  1. 1.
    Akram AH, Fitzpatrick AJ, Halford FR (1998) A model to predict wireline formation tester sample contamination. In: SPE annual technical conference and exhibition, New Orleans, Louisiana, 27–30 Sept 1998, SPE-48959-MSGoogle Scholar
  2. 2.
    Agrawal S, Coskun SB, Hunnur AT (2012) Simulation modeling for optimized lwd fluid sampling under different invasion profiles. In: Abu Dhabi international petroleum conference and exhibition, Abu Dhabi, UAE, 11–14 Nov 2012, SPE-162345-MSGoogle Scholar
  3. 3.
    Yang M, Daoyong Yang D (2016) Permeability interpretation from wireline formation testing measurements with consideration of effective thickness. Soc Petrophys Well-Log Anal 57(3), June 2016, SPWLA-2016-v57n3a3Google Scholar
  4. 4.
    Canas JA, Low S, Adur N, Teixeira VL (2005) Viscous oil dynamics evaluation for better fluid sampling. In: SPE international thermal operations and heavy oil symposium, Calgary, Alberta, Canada, 1–3 Nov 2005, SPE-97767-MSGoogle Scholar
  5. 5.
  6. 6.
    McCalmont S, Onu CO, Wu J, Kiome P, Sheng JJ, Adegbola OA, Rajasingham R, Lee J (2005) Analysis for an efficient sampling operation: prejob modeling through a near-wellbore simulator. In: SPE annual technical conference and exhibition, Dallas, Texas, 9–12 Oct 2005, SPE-95885-MSGoogle Scholar
  7. 7.
    Khan WA, Wattenbarger RA, Shahbir S, Agha S, Akram H (2011) An improved model for wireline formation tester pumpout time estimation. In: SPE annual technical conference and exhibition, Denver, Colorado, USA, 30 Oct–2 Nov 2011, SPE-147029-MSGoogle Scholar
  8. 8.
    Phelps GD (1995) Computation of mud filtrate invasion profiles. J Can Pet Technol January 1995, PETSOC-95-01-02Google Scholar
  9. 9.
    Li S, Shen LC (2003) Dynamic invasion profiles and time-lapse electrical logs. In: SPWLA 44th annual logging symposium, Galveston, Texas, 22–25 June 2003, SPWLA-2003-EGoogle Scholar
  10. 10.
    Tran HN, Tran LV, Nguyen TV, Tran ND, Tran DV, Hardikar NP, Coskun SB (2014) Fast yet clean downhole heavy oil samples from wireline formation tester using selective slug sampling technique. In: SPE international heavy oil conference and exhibition, Mangaf, Kuwait, 8–10 Dec 2014, SPE-172874-MSGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • X. Wang
    • 1
  • G. Lei
    • 2
    Email author
  • N. P. Hardikar
    • 3
  • R. DiFoggio
    • 4
  • X. Zeng
    • 2
  1. 1.CNOOC ShenzhenGuangdongChina
  2. 2.Baker Hughes, a GE CompanyShenzhenChina
  3. 3.Baker Hughes, a GE CompanyKuala LumpurMalaysia
  4. 4.Baker Hughes, a GE CompanyHoustonUSA

Personalised recommendations