نوع مقاله : مقاله مروری
نویسندگان
1 Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
2 Department of Geology, Faculty of Science, Ferdowsi University of Mashhad
3 Department of Geology, Faculty of Sciences, Ferdowsi Mashhad University, Mashhad, Iran
4 Geoscience Division, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract:
Shallow Water Flow (SWF) is a type of geohazard in hydrocarbon exploration in deep-water basins. This problem occurs in deep-water basins with high sedimentation rates. When the drill hits overpressured layers below the seabed, large volumes of water and sand flow along the wellbore and ultimately loss of well integrity. This is the first study to review the literature on predicting SWF predrilling from different aspects. We also evaluate the SWF problem in the channel by using 3D seismic attributes and the post-stack inversion method in the South Caspian Basin (SCB) as an example of a deep-water basin prone to SWF geohazard. The results of the literature show that geological settings with rapid subsidence are the settings more likely to be associated with SWF. Compaction disequilibrium, differential compaction, and hyperpressure are the mechanisms of SWF. The most important quantitative criteria for identifying the SWF environments are P-impedance (AI), S-impedance (SI), Vp/Vs, and Poisson's ratios. Post-stack and pre-stack inversion are the most important techniques for evaluating SWF by seismic data. The results of attribute studies revealed that the sweetness and RMS amplitude are the best attributes for the identification of buried channels prone to SWF problem. Also, post-stack inversion results show SWF problem (low impedance zones; AI<3150((m/s)*(g/cc)) in the central and eastern parts of the buried channel in the SCB. The predicted SWF sands in this study match with the SWF zone were experienced during exploratory drilling. The review findings provide a proper understanding of SWF geohazard in deep-water basins and may be useful for other researchers and decrease the drilling risk in future works in the SCB. As recommended in this review, further review research should be done to stabilize shallow water flow zone during the drilling operation.
Abstract:
Shallow Water Flow (SWF) is a type of geohazard in hydrocarbon exploration in deep-water basins. This problem occurs in deep-water basins with high sedimentation rates. When the drill hits overpressured layers below the seabed, large volumes of water and sand flow along the wellbore and ultimately loss of well integrity. This is the first study to review the literature on predicting SWF predrilling from different aspects. We also evaluate the SWF problem in the channel by using 3D seismic attributes and the post-stack inversion method in the South Caspian Basin (SCB) as an example of a deep-water basin prone to SWF geohazard. The results of the literature show that geological settings with rapid subsidence are the settings more likely to be associated with SWF. Compaction disequilibrium, differential compaction, and hyperpressure are the mechanisms of SWF. The most important quantitative criteria for identifying the SWF environments are P-impedance (AI), S-impedance (SI), Vp/Vs, and Poisson's ratios. Post-stack and pre-stack inversion are the most important techniques for evaluating SWF by seismic data. The results of attribute studies revealed that the sweetness and RMS amplitude are the best attributes for the identification of buried channels prone to SWF problem.
کلیدواژهها [English]
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