Petrography and Biostratigraphy of #101 Las Cañas and Mesita #1 cores, Golden Lane/Poza Rica Trend, Mexico

Petrographic analysis of two cores (Cañas #101 and Mesita #1) from the Golden Lane (Faja del Oro)/Poza Rica oil fields (Cañas and Mesa Cerrada) along the Tuxpan Platform, Mexico reveals that Lower/Middle Cretaceous reefs developed along the margin of the Platform at this time. One facies in this complex (the El Abra Limestones) contains abundant rudists, corals, and benthic/planktic foraminfers. This facies has yielded huge volumes of hydrocarbons. For example, the Potrero del Llano #4, blew out in December, 1910 at a rate exceeding 100,000 BO/day. It produced 93 million BO, and is possibly the most productive well ever drilled. Thin sections cut from the #101 Cañas cores (Cores 1-4; 6-7; 9-11; 13-17) demonstrate the following petrographic trends: #1; foraminiferal mudstone with sparite-filled fractures; #2; angular quartz in foraminiferal mudstone; #3; chert overlain by foraminiferal ooze; #4; Cuneolina sp. and Miliolidae; #6; Barkerina barkerensis (Albian); #7, Dictyoconus sp. with gastropods and spar cement; # 9; bitumen with dogtooth spar and bryozoa; #10; bryozoans with moldic porosity; #11; pelletoidal boundstone with limestone clasts and rim cement; #13; corals and meniscus cement in interparticle porosity; #14; oolitic grainstone with oil stains along stylolites; #15; rudists in oil shale with metamorphic quartz clasts; #16; lithic arenite with hematite cement; and #17; subarkose with granite fragments and angular quartz. The other core (Mesita #1-Cores 2, 4 and 5) exhibits these variations: #2; Cuneolina sp. with spar cement; #4; orbulinid foraminifers and rudists; and #5; Dictyoconus sp. with spar cement. The thin sections from the #101 Las Cañas and Mesita #1 cores allow insight into a portion of the giant Pimienta-Tamabra (!) petroleum system in the Tampico/Misantla Basin, Mexico. The total reserves of this system are ~ 66.3 BBO and 103.7 TCF of natural gas. This is ~ 836 BBOE.