Estimation Pore and Fracture Pressure Based on Log Data; Case Study: Mishrif Formation/Buzurgan Oilfield at Iraq
DOI:
https://doi.org/10.31699/IJCPE.2023.1.8Keywords:
Pore pressure, Fracture pressure, Overburden pressure, Clay volume, Eaton method, Sonic log, Resistivity log, Abnormal pressure.Abstract
Prediction of the formation of pore and fracture pressure before constructing a drilling wells program are a crucial since it helps to prevent several drilling operations issues including lost circulation, kick, pipe sticking, blowout, and other issues. IP (Interactive Petrophysics) software is used to calculate and measure pore and fracture pressure. Eaton method, Matthews and Kelly, Modified Eaton, and Barker and Wood equations are used to calculate fracture pressure, whereas only Eaton method is used to measure pore pressure. These approaches are based on log data obtained from six wells, three from the north dome; BUCN-52, BUCN-51, BUCN-43 and the other from the south dome; BUCS-49, BUCS-48, BUCS-47. Along with the overburden pressure gradient and clay volume, which were also established first, data such as gamma ray, density, resistivity, and sonic log data are also required. A key consideration in the design of certain wells is the forecasting of fracture pressure for wells drilled in the southern Iraqi oilfield of Buzurgan. The pressure abnormality is found in MA, MB21, MC1 and MC2 units by depending on pore pressures calculated from resistivity log. In these units, depths and its equivalent normal and abnormal pressure are detected for all six selected wells; BUCS-47, BUCS-48, BUCS-49, BUCN-43, BUCN-51 and BBCN-52. For MA, MB21, MC1, and MC2 units, the highest difference in pore pressure values are 1698 psi @ 3750 m (BUCN-51), 3420 psi @ 3900 m (BUCN-51), 788 psi @ 3980 m (BUCS-49), and 5705 psi @ 4020 m (BUCN-52). On other hands, MB11 and MB12 units have normal pressure trend in all studied wells. Finally, the results show that the highest pore and fracture pressure values is existed in North dome, in comparison with that obtained in south dome of Mishrif reservoir at Buzurgan oilfield.
Received on 27/07/2022
Received in Revised Form on 03/10/2022
Accepted on 03/10/2022
Published on 30/03/2023
References
Tomar P.S., Kapoor Deepak and Mallik Sarvesh, “Pore Pressure Prediction and analysis of High Pressure Formation using wire line logs: A case study of Tripura-Cachar fold belt of Assam Arakan basin”, SPG India, Jaipur 2017.
Nagham J. A., “A Study of Fracture Pressure Gradient for Deep Wells in southern Iraqi oil fields”, MS.C Thesis, University of Baghdad, 2004.
V. Atashbari, M.Tingay, “Pore Pressure Prediction in Carbonate Reservoirs”, Australian School of Petroleum, SPE 150835, 2012, https://doi.org/10.2118/150835-MS.
Abdoulshakour Nour and Nasher AIBinHassan, "Seismic Attributes and Advanced Computer Algorithm Method to Predict Formation Pore Pressure: Paleozoic Sediments of Northwest Saudi Arabia" IPTC 16680, Saudi Aramco, 2013, https://doi.org/10.3997/2214-4609-pdb.350.iptc16680.
Hussein I. J., 2012. “Building a Geological Model for the Buzurgan Oil Field/ Mishirif Formation”, University of Baghdad/College of Engineering/Petroleum Department, M.Sc. degree.
Ahmed Kareem Hasan, “A Study of Abnormal Formation Pressures Distribution and Their Effect on Drilling Operation in Middle & South Iraqi Oil Fields”, MSC Thesis, petroleum Engineer, College of Engineer, University of Baghdad, 2016.
Institute of petroleum Eng., “Formation Pressure 5”, Heriot Watt University, 2002.
Diana Morton-Thompson and Arnold M. Woods, “Development Geology Reference Manual”, June 2013.
Dickey, P. A., Cox, W. C., “Oil and gas reservoirs with subnormal pressures”: AAPG Bulletin, v. 61, n. 12, p. 2134–2142, 1977, https://doi.org/10.1306/C1EA47D9-16C9-11D7-8645000102C1865D.
Neaam Faik Hussain, “Estimating of Pore Pressure Gradient and the Effect of Abnormal Pore Pressure on Drilling Operations in Southern-East Borders Iraqi Oilfields”, MSC Thesis, petroleum Engineer, College of Engineer, University of Baghdad, 2018.
Schlumberger, “Interactive Petrophysics Manual”, Senergy Ltd, 2008.
Rafiad K. A., “Prediction of Abnormal Formation Pressure in Southern Iraq”, MS.C Thesis, University of Baghdad, 1996.
Rakesh R. R. and Dr. C. Chandrashekhar, “Pore Pressure Prediction a case Study in Cambay Basion”, Indian oil Corporation limited, January 2015.
Ben A. Eaton, "Graphical Method Predicts Geopressure World Wide", World Oil, July 1976, pp. (100-104).
Downloads
Published
Issue
Section
License
Copyright (c) 2023 Iraqi Journal of Chemical and Petroleum Engineering
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
