Modified Sequence Stratigraphic Techniques Permit Correlation of Basinal Stratigraphy: Example from the Cretaceous of the Campeche Basin Mexico

Richard A. Schatzinger¹, Alberto O. Chernikoff², Arturo Bustos Vazquez³, Eduardo Aguirre Cerda³, and Jesus Garcia Hernandez^3
1Consultant, Copan, OK
²Schlumberger, DCS, Tampico, Mexico
³Pemex, Cd. del Carmen, Mexico

In basinal settings, such as in dolomitized Lower and Middle Cretaceous carbonates of the Campeche Basin located west of the Yucatan Peninsula, accommodation space is essentially infinite and cycle to sequence thicknesses are controlled by pulses of sediment reworked into the basin primarily during lowstand. Stratigraphic subdivisions of the Lower and Middle Cretaceous at Cantarell Field tend to be thinner than can be easily described with seismic data. For this reason we have developed a technique using image logs as well as the normal suite of wireline logs to define depositional periodicity. The reduced number of depositional facies within the basinal setting has allowed us to extrapolate core control and measure the thickness of depositional cycles on image logs. Cycles consist of debris flows and carbonate turbidites separated by thin argillaceous pelagic intervals. On a sub-regional scale the image log data for the Middle Cretaceous consists of alternating vertical successions with thicker than normal cycles (deposited primarily during sea level lowstand) and intervals with thinner than normal cycles (deposited primarily during sea level highstand). Correlation of these genetic packages mimics the regional westward prograding clinoform geometry that can be seen in seismic displays. Correlation of Gamma Ray log cycles within the growth-faulted Lower Cretaceous at Cantarell, where only a small amount of relevant core control is available, demonstrates thickening (growth) on eastern margins of fault blocks and an increased number of stratigraphically deep channel sequences in the southeastern part of the field. Twenty-four log-defined Lower Cretaceous sequences, each 30-50m thick, have average durations of about 1.3 million years, placing them within the general range of third order depositional sequences

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas