{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T17:13:35Z","timestamp":1772730815996,"version":"3.50.1"},"reference-count":63,"publisher":"Geological Society of London","issue":"4","license":[{"start":{"date-parts":[[2019,10,28]],"date-time":"2019-10-28T00:00:00Z","timestamp":1572220800000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-002"}],"content-domain":{"domain":["www.lyellcollection.org"],"crossmark-restriction":true},"short-container-title":["PG"],"published-print":{"date-parts":[[2019,11]]},"abstract":"<jats:p>Fracture scaling parameters are an important input for modelling of naturally fractured reservoirs, but are very difficult to derive from subsurface data. Extensive areas of exposure in the northern Kurdistan Region of Iraq provide useful outcrop analogues for nearby producing and potential hydrocarbon fields. A variety of data acquisition methods are used to analyse fracture systems in carbonates of the Upper Cretaceous Aqra\u2013Bekhme Formation across a wide range of scales. When plotted on length\u2013intensity graphs, the collated data lie below an upper envelope that follows a power-law distribution over five orders of magnitude between 0.1 and 3000\u2005m, and which defines the maximum likely intensity of background fracturing across the region. Contouring the length\u2013intensity data shows the distribution of intensities below the upper envelope, and allows modal and minimum likely intensities to be estimated. Likely causes for the observed variation in fracture intensities include the domainal nature of deformation, the proximity to high strain zones including faults, second-order effects such as ladder fractures, and variations in the thickness of mechanical layering.<\/jats:p>\n                  <jats:p content-type=\"thematic-collection\">\n                    <jats:bold>Thematic collection:<\/jats:bold>\n                    This article is part of the Naturally Fractured Reservoirs collection available at:\n                    <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/www.lyellcollection.org\/cc\/naturally-fractured-reservoirs\">https:\/\/www.lyellcollection.org\/cc\/naturally-fractured-reservoirs<\/jats:ext-link>\n                  <\/jats:p>","DOI":"10.1144\/petgeo2018-168","type":"journal-article","created":{"date-parts":[[2019,9,6]],"date-time":"2019-09-06T09:55:12Z","timestamp":1567763712000},"page":"429-442","update-policy":"https:\/\/doi.org\/10.1144\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["Multiscale fracture length analysis in carbonate reservoir units, Kurdistan, NE Iraq"],"prefix":"10.1144","volume":"25","author":[{"given":"Jonathan J.","family":"Long","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4595-2489","authenticated-orcid":false,"given":"Richard R.","family":"Jones","sequence":"additional","affiliation":[]},{"given":"David M.","family":"Oxlade","sequence":"additional","affiliation":[]},{"given":"Susie E.","family":"Daniels","sequence":"additional","affiliation":[]},{"given":"S\u00e9bastien R.","family":"Gilment","sequence":"additional","affiliation":[]}],"member":"1881","published-online":{"date-parts":[[2019,10,28]]},"reference":[{"key":"e_1_3_4_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.palaeo.2008.04.021"},{"key":"e_1_3_4_3_1","volume-title":"The Petroleum Geology of Iraq","author":"Aqrawi A.A.","year":"2010","unstructured":"Aqrawi, A.A., Goff, J.C., Horbury, A.D. & Sadooni, F.N. 2010. The Petroleum Geology of Iraq. Scientific Press, Beaconsfield, UK."},{"key":"e_1_3_4_4_1","doi-asserted-by":"crossref","unstructured":"Araujo H. Lacentre P. et al. 2004. Dynamic behavior of discrete fracture network (DFN) models. Paper presented at the SPE International Petroleum Conference 7\u20139 November 2004 Puebla Pue Mexico https:\/\/doi.org\/10.2118\/91940-MS","DOI":"10.2118\/91940-MS"},{"key":"e_1_3_4_5_1","doi-asserted-by":"publisher","DOI":"10.1029\/2009TC002482"},{"key":"e_1_3_4_6_1","doi-asserted-by":"publisher","DOI":"10.1144\/petgeo2012-036"},{"key":"e_1_3_4_7_1","unstructured":"Baecher G.B. & Lanney N.A. 1978. Trace length biases in joint surveys. In: Proceedings of the 19th U.S. Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association Alexandria VA 56\u201365."},{"key":"e_1_3_4_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2015.05.013"},{"key":"e_1_3_4_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cageo.2017.02.019"},{"key":"e_1_3_4_10_1","doi-asserted-by":"publisher","DOI":"10.1144\/0016-764902-110"},{"key":"e_1_3_4_11_1","doi-asserted-by":"publisher","DOI":"10.1029\/1999RG000074"},{"key":"e_1_3_4_12_1","doi-asserted-by":"publisher","DOI":"10.1029\/96WR00433"},{"key":"e_1_3_4_13_1","doi-asserted-by":"crossref","first-page":"ETG4-1","DOI":"10.1029\/2001JB000176","article-title":"A statistical scaling model for fracture network geometry, with validation on a multiscale mapping of a joint network (Hornelen Basin, Norway)","volume":"107","author":"Bour O.","year":"2002","unstructured":"Bour, O., Davy, P., Darcel, C. & Odling, N. 2002. A statistical scaling model for fracture network geometry, with validation on a multiscale mapping of a joint network (Hornelen Basin, Norway). Journal of Geophysical Research: Solid Earth, 107, ETG4-1\u2013ETG4-12, https:\/\/doi.org\/10.1029\/1999RG000074","journal-title":"Journal of Geophysical Research: Solid Earth"},{"key":"e_1_3_4_14_1","doi-asserted-by":"publisher","DOI":"10.1144\/petgeo.7.S.S43"},{"key":"e_1_3_4_15_1","first-page":"65","volume-title":"Monograph on Rock Mechanic Application in Mining","author":"Call R.D.","year":"1976","unstructured":"Call, R.D., Savely, J.P. & Nicolas, D.E. 1976. Estimation of joint set characteristics from surface mapping data. In: Hustrulid, W.A. (ed.) Monograph on Rock Mechanic Application in Mining. AIME, New York, 65\u201373."},{"key":"e_1_3_4_16_1","doi-asserted-by":"crossref","first-page":"B08409","DOI":"10.1029\/2011JB009041","article-title":"Roughness of fault surfaces over nine decades of length scales","volume":"117","author":"Candela T.","year":"2012","unstructured":"Candela, T., Renard, F., Klinger, Y., Mair, K., Schmittbuhl, J. & Brodsky, E.E. 2012. Roughness of fault surfaces over nine decades of length scales. Journal of Geophysical Research: Solid Earth, 117, B08409, https:\/\/doi.org\/10.1029\/2011JB009041","journal-title":"Journal of Geophysical Research: Solid Earth"},{"key":"e_1_3_4_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/0040-1951(95)00177-8"},{"key":"e_1_3_4_18_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-94-009-0791-1_26"},{"key":"e_1_3_4_19_1","doi-asserted-by":"publisher","DOI":"10.1137\/070710111"},{"key":"e_1_3_4_20_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2017.09.009"},{"key":"e_1_3_4_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/0148-9062(77)90004-3"},{"key":"e_1_3_4_22_1","unstructured":"Dershowitz W.S. & Herda H.H. 1992. Interpretation of fracture spacing and intensity. Paper presented at the 33th US Symposium on Rock Mechanics (USRMS) 3\u20135 June 1992 Santa Fe New Mexico USA."},{"key":"e_1_3_4_23_1","series-title":"AAPG Special Publications","first-page":"1194","volume-title":"Habitat of Oil","author":"Dunnington H.V.","year":"1958","unstructured":"Dunnington, H.V. 1958. Generation, migration, accumulation and dissipation of oil in northern Iraq. In: Weeks, G.L. (ed.) Habitat of Oil. AAPG Special Publications, 18, 1194\u20131251."},{"key":"e_1_3_4_24_1","doi-asserted-by":"publisher","DOI":"10.1306\/06271413205"},{"key":"e_1_3_4_25_1","doi-asserted-by":"publisher","DOI":"10.1016\/0040-1951(93)90114-Y"},{"key":"e_1_3_4_26_1","doi-asserted-by":"publisher","DOI":"10.1144\/GSL.SP.1999.155.01.05"},{"key":"e_1_3_4_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0191-8141(00)00090-0"},{"key":"e_1_3_4_28_1","doi-asserted-by":"publisher","DOI":"10.1130\/0016-7606(2007)119[1387:TFILCR]2.0.CO;2"},{"key":"e_1_3_4_29_1","series-title":"Geological Society, London, Special Publications","first-page":"215","volume-title":"Fractography: Fracture Topography as a Tool in Fracture Mechanics and Stress Analysis","author":"Gross M.R.","year":"1995","unstructured":"Gross, M.R., Fisher, M.P., Engelder, T. & Greenfield, R.J. 1995. Factors controlling joint spacing in interbedded sedimentary rocks: integrating numerical models with field observations from the Monterey Formation, USA. In: Ameen, M.S. (ed.) 1995. Fractography: Fracture Topography as a Tool in Fracture Mechanics and Stress Analysis. Geological Society, London, Special Publications, 92, 215\u2013233, https:\/\/doi.org\/10.1144\/GSL.SP.1995.092.01.12"},{"key":"e_1_3_4_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tecto.2011.01.003"},{"key":"e_1_3_4_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/0191-8141(85)90048-3"},{"key":"e_1_3_4_32_1","doi-asserted-by":"crossref","unstructured":"Heffer K.J. & Bevan T.G. 1990. Scaling relationships in natural fractures \u2013 Data theory and applications. Paper SPE 20981 presented at the European Petroleum Conference 21\u201324 October 1990 The Hague Netherlands.","DOI":"10.2118\/20981-MS"},{"key":"e_1_3_4_33_1","volume-title":"Geology of Iraq","author":"Jassim S.Z.","year":"2006","unstructured":"Jassim, S.Z. & Goff, J.C. 2006. Geology of Iraq. Dolin, Prague, Czech Republic."},{"key":"e_1_3_4_34_1","doi-asserted-by":"publisher","DOI":"10.2110\/sepmcsp.10.031"},{"key":"e_1_3_4_35_1","doi-asserted-by":"publisher","DOI":"10.1130\/GES01247.1"},{"key":"e_1_3_4_36_1","doi-asserted-by":"publisher","DOI":"10.1080\/01621459.1958.10501452"},{"key":"e_1_3_4_37_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF01032335"},{"key":"e_1_3_4_38_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2011.01.012"},{"key":"e_1_3_4_39_1","unstructured":"Long J.J Jones R.R. & Daniels S.E. 2018. Reducing uncertainty in fracture modelling: assessing the sensitivity of inputs from outcrop analogues. Paper presented at the Geology of Fractured Reservoirs Conference 24\u201325 October 2018 London UK."},{"key":"e_1_3_4_40_1","first-page":"109","article-title":"Fracture formation and evolution in crystalline rocks: Insights from attribute analysis","volume":"214","author":"McCaffrey K.J.W.","year":"2003","unstructured":"McCaffrey, K.J.W., Sleight, J.M., Pugliese, S. & Holdsworth, R.E. 2003. Fracture formation and evolution in crystalline rocks: Insights from attribute analysis. In: Petford, N. & McCaffrey, K.J.W. (eds) 2003. Hydrocarbons in Crystalline Rocks. Geological Society, London, Special Publications, 214, 109\u2013124, https:\/\/doi.org\/10.1144\/GSL.SP.2003.214.01.07","journal-title":"Hydrocarbons in Crystalline Rocks"},{"key":"e_1_3_4_41_1","doi-asserted-by":"publisher","DOI":"10.1144\/0016-764905-017"},{"key":"e_1_3_4_42_1","first-page":"2367","article-title":"Small-scale fracture density in Asmari Formation of Southwest Iran and its relation to bed thickness and structural setting","volume":"57","author":"McQuillan H.","year":"1973","unstructured":"McQuillan, H. 1973. Small-scale fracture density in Asmari Formation of Southwest Iran and its relation to bed thickness and structural setting. AAPG Bulletin, 57, 2367\u20132385, http:\/\/doi.org\/10.1306\/83d9131c-16c7-11d7-8645000102c1865d","journal-title":"AAPG Bulletin"},{"key":"e_1_3_4_43_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tecto.2012.01.022"},{"key":"e_1_3_4_44_1","doi-asserted-by":"publisher","DOI":"10.1016\/0191-8141(91)90055-N"},{"key":"e_1_3_4_45_1","volume-title":"Geologic Analysis of Naturally Fractured Reservoirs","author":"Nelson R.","year":"2001","unstructured":"Nelson, R. 2001. Geologic Analysis of Naturally Fractured Reservoirs. Gulf Professional Publishing, Houston, TX."},{"key":"e_1_3_4_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0191-8141(97)00041-2"},{"key":"e_1_3_4_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/0148-9062(81)90976-1"},{"key":"e_1_3_4_48_1","doi-asserted-by":"publisher","DOI":"10.1016\/0040-1951(95)00030-Q"},{"key":"e_1_3_4_49_1","doi-asserted-by":"publisher","DOI":"10.1144\/SP421.14"},{"key":"e_1_3_4_50_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-94-011-1498-1"},{"key":"e_1_3_4_51_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2016.12.005"},{"key":"e_1_3_4_52_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2015.01.005"},{"key":"e_1_3_4_53_1","series-title":"GeoArabia Special Publications","volume-title":"Arabian Plate Sequence Stratigraphy","author":"Sharland P.R.","year":"2001","unstructured":"Sharland, P.R., Archer, R. et al. 2001. Arabian Plate Sequence Stratigraphy. GeoArabia Special Publications, 2. Gulf PetroLink, Manama, Bahrain."},{"key":"e_1_3_4_54_1","first-page":"343","article-title":"Stratigraphic architecture and fracture-controlled dolomitization of the Cretaceous Khami and Bangestan groups: an outcrop case study, Zagros Mountains, Iran","volume":"329","author":"Sharp I.","year":"2010","unstructured":"Sharp, I., Gillespie, P. et al. 2010. Stratigraphic architecture and fracture-controlled dolomitization of the Cretaceous Khami and Bangestan groups: an outcrop case study, Zagros Mountains, Iran. In: van Buchem, F.S.P., Gerdes, K.D. & Esteban, M. (eds) 2010. Mesozoic and Cenozoic Carbonate Systems of the Mediterranean and the Middle East: Stratigraphic and Diagenetic Reference Models. Geological Society, London, Special Publications, 329, 343\u2013396, https:\/\/doi.org\/10.1144\/SP329.14","journal-title":"Mesozoic and Cenozoic Carbonate Systems of the Mediterranean and the Middle East: Stratigraphic and Diagenetic Reference Models"},{"key":"e_1_3_4_55_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jsg.2017.07.009"},{"key":"e_1_3_4_56_1","first-page":"97","volume-title":"NSF Advanced Science Seminar in Rock Mechanics for College Teachers of Structural Geology","author":"Stearns D.W.","year":"1968","unstructured":"Stearns, D.W. 1968. Certain aspects of fracture in naturally deformed rocks. In: Riecker, R.E. (ed.) NSF Advanced Science Seminar in Rock Mechanics for College Teachers of Structural Geology. Air Force Cambridge Research Laboratories, Bedford, MA, 1, 97\u2013118."},{"key":"e_1_3_4_57_1","doi-asserted-by":"publisher","DOI":"10.1306\/M16371C8"},{"key":"e_1_3_4_58_1","doi-asserted-by":"publisher","DOI":"10.1306\/06231413113"},{"key":"e_1_3_4_59_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.marpetgeo.2011.04.003"},{"key":"e_1_3_4_60_1","volume-title":"Stratigraphic Lexicon of Iraq","author":"van Bellen R.C.","year":"1959","unstructured":"van Bellen, R.C., Dunnington, H.V., Wetzel, R. & Morton, D.M. 1959. Stratigraphic Lexicon of Iraq. Gulf PetroLink, Manama, Bahrain."},{"key":"e_1_3_4_61_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-0-387-21736-9"},{"key":"e_1_3_4_62_1","first-page":"EGU2013-10445","volume-title":"Geophysical Research Abstracts","author":"Watson F.","year":"2013","unstructured":"Watson, F., Long, J., Jarvis, Z., Wilkinson, M. & Jones, R. 2013. Variability in interpretations when picking fractures from satellite images. Geophysical Research Abstracts, 15, EGU2013-10445, https:\/\/meetingorganizer.copernicus.org\/EGU2013\/EGU2013-10445.pdf"},{"key":"e_1_3_4_63_1","doi-asserted-by":"publisher","DOI":"10.1144\/1354-079305-675"},{"key":"e_1_3_4_64_1","doi-asserted-by":"publisher","DOI":"10.1016\/0191-8141(94)00099-L"}],"container-title":["Petroleum Geoscience"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.lyellcollection.org\/doi\/pdf\/10.1144\/petgeo2018-168","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T16:17:22Z","timestamp":1772727442000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.lyellcollection.org\/doi\/10.1144\/petgeo2018-168"},"secondary":[{"URL":"https:\/\/geoscienceworld.org\/pg\/article-lookup?doi=10.1144\/petgeo2018-168","label":"geoscienceworld"}]},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,10,28]]},"references-count":63,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2019,11,1]]},"published-print":{"date-parts":[[2019,11]]}},"alternative-id":["10.1144\/petgeo2018-168"],"URL":"https:\/\/doi.org\/10.1144\/petgeo2018-168","relation":{},"ISSN":["1354-0793","2041-496X"],"issn-type":[{"value":"1354-0793","type":"print"},{"value":"2041-496X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,10,28]]},"assertion":[{"value":"2018-11-09","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-06-23","order":1,"name":"revised","label":"Revised","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-09-04","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-10-28","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}