3D Seismic Pore Pressure Analysis in Offshore Arenque Field, Mexico
Authors: Lopez-Solis Victor , Velazquez-cruz David , Martinez-Gonzalez Fabian , Espinosa-Castaneda Gustavo , Diaz Viera Martin Alberto 
Published: April 2012

Abstract
The Arenque marine field is located 30 km offshore in the East part of Tampicocity. It is part of Tampico-Misantla basin and it produces 30°API oil. Theproducer reservoirs are Jurassic San Andres made up by grainstone and lowerCretaceous Tamaulipas composite by naturally fractured fine-grainedlimestone.
In 2004 PEMEX started a 3D seismic gathering, concluding in 2009 with a newreinterpreted geologic static model of San Andres and lower Tamaulipasreservoirs. The objective of 3D seismic was both, to explore new opportunities, and to accelerate the recovery of remaining reserves of the Arenque field. As aresult of the reinterpretation, new paths of horizontal wells were defined, anda drilling program was worked out from 2010 to 2018 to drill both developed andinfill wells as well as reentries.
At the beginning of the present century, PEMEX drilled several horizontal wellsin the Arenque field with drilling times above 150 days. These drilling timeshad non-productive times originated by pore pressure and well instabilityproblems. In this paper we presented a pore pressure analysis using 3D seismiccompiled in the Arenque field. The aims of the analysis were both to visualizeand quantify the behavior of geopressures in the field to redefine drillingdesigns of horizontal wells and to avoid non-productive times that duplicatedprogrammed drilling times in the past. Within the analysis was defined thenormal compaction trends for interval velocity, and also the pore pressuremodels were fixed to geological conditions of the marine portion of theTampico-Misantla basin.

Introduction
Tampico Misantla basin including offshore area has 50,000 square kilometers andit is the oldest oil production zone in Mexico. Into this basin, explorationactivity began in 1904 in Ebano-Panuco province which had produced more than1,000 million of heavy crude oil from upper cretaceous calcareous rocks. Also, the basin produce in lower cretaceous and kimmeridgian carbonate rocks like inTamaulipas-Constituciones and Arenque fields. At the south portion of thebasin, it is situated the Golden Lane, discovered in 1908 whose productioncomes from middle cretaceous reef carbonate rocks. The Golden Lane have both anonshore and offshore portion with fields like Cerro Azul, Alamo, Alazan, Temapache, Santa Agueda in onshore part and Carpa, Bagre, Mejillon, Atun inoffshore. Bordering the Golden Lane, we find other important fields such asTres Hermanos, Poza Rica and San Andres whose oil production comes fromcarbonates into stratigraphic traps. At the occident of Golden Lane, it wasdeveloped the Chicontepec Paleochannel with an extent of 3,000 squarekilometers. The Chicontepec Paleochannel is made up by siliciclastic sedimentsof Paleocene and Eocene ages. The Tampico-Misantla basin recorded an averageproduction in 2011 of 90,000 barrels of oil equivalent per day (BOEPD) afterhaving reached a maximum of 600,000 barrels of oil per day (BOPD) in 1921. Nowadays, the basin has an accumulated production of 6,000 million barrels ofoil equivalent (BOE) and the total remaining reserves are 18,000 million BOE. Figure 1(a) depicts Tampico-Misantla basin and the location of their mainfields (PEMEX 2004, 2008, 2010, 2011a; Schlumberger, 1984).