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Title: Modeling tip zones to predict the throw and length characteristics of faults

Abstract

A map of faults in a 60 km{sup 2} area of the southern North Sea has been produced from three-dimensional seismic data. The faults shown on the map obey power-law cumulative-frequency distributions for throw (power-law exponent, D, {approx} 2.7) and length (D {approx} 1.1). Simulations have been carried out to correct for sampling biases in the data and to make predictions of the throw the data and to make predictions of the throw and length scaling characteristics of the faults. The most important bias is caused by poor resolution of the small displacement tip zones of faults. The raw data show considerable scatter in their length: throw ratios, but they more closely fit a linar relationship if a length of 500 m is added to each fault, thereby making up for the zones near the fault tips with throws ({approx} 15 m) below seismic resolution. Further variability in the data may be caused by such geological factors as fault interaction. Tip lengths have been extended to simulate the actual fault pattern in the study area. Maps produced by this procedure can be used to estimate the true connectivity of the fault network. Extending the faults results in greater connectivity thanmore » shown by the raw data, which may cause greater compartmentalization of the rock mass. This greater compartmentalization has implications for hydrocarbon exploitation if the faults are sealing. A problem with the model, however, is that it does not deal effectively with the interaction of subparallel, noncoplanar faults. To test the reliability of the procedure, we analyzed exposure-scale faults in Somerset, United Kingdom, where the tips are well constrained. Both length-throw relationships and map-pattern connectivity for the simulated fault networks agree closely with the actual data.« less

Authors:
; ;  [1]
  1. Univ. of Southampton (United Kingdom); and others
Publication Date:
OSTI Identifier:
433074
Resource Type:
Journal Article
Journal Name:
AAPG Bulletin
Additional Journal Information:
Journal Volume: 81; Journal Issue: 1; Other Information: PBD: Jan 1997
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 03 NATURAL GAS; GEOLOGIC FAULTS; GEOMETRY; RESOURCE POTENTIAL; NORTH SEA; SEISMIC SURVEYS; HYDROCARBONS; EXPLORATION

Citation Formats

Pickering, G, Sanderson, D J, and Bull, J M. Modeling tip zones to predict the throw and length characteristics of faults. United States: N. p., 1997. Web.
Pickering, G, Sanderson, D J, & Bull, J M. Modeling tip zones to predict the throw and length characteristics of faults. United States.
Pickering, G, Sanderson, D J, and Bull, J M. 1997. "Modeling tip zones to predict the throw and length characteristics of faults". United States.
@article{osti_433074,
title = {Modeling tip zones to predict the throw and length characteristics of faults},
author = {Pickering, G and Sanderson, D J and Bull, J M},
abstractNote = {A map of faults in a 60 km{sup 2} area of the southern North Sea has been produced from three-dimensional seismic data. The faults shown on the map obey power-law cumulative-frequency distributions for throw (power-law exponent, D, {approx} 2.7) and length (D {approx} 1.1). Simulations have been carried out to correct for sampling biases in the data and to make predictions of the throw the data and to make predictions of the throw and length scaling characteristics of the faults. The most important bias is caused by poor resolution of the small displacement tip zones of faults. The raw data show considerable scatter in their length: throw ratios, but they more closely fit a linar relationship if a length of 500 m is added to each fault, thereby making up for the zones near the fault tips with throws ({approx} 15 m) below seismic resolution. Further variability in the data may be caused by such geological factors as fault interaction. Tip lengths have been extended to simulate the actual fault pattern in the study area. Maps produced by this procedure can be used to estimate the true connectivity of the fault network. Extending the faults results in greater connectivity than shown by the raw data, which may cause greater compartmentalization of the rock mass. This greater compartmentalization has implications for hydrocarbon exploitation if the faults are sealing. A problem with the model, however, is that it does not deal effectively with the interaction of subparallel, noncoplanar faults. To test the reliability of the procedure, we analyzed exposure-scale faults in Somerset, United Kingdom, where the tips are well constrained. Both length-throw relationships and map-pattern connectivity for the simulated fault networks agree closely with the actual data.},
doi = {},
url = {https://www.osti.gov/biblio/433074}, journal = {AAPG Bulletin},
number = 1,
volume = 81,
place = {United States},
year = {1997},
month = {1}
}