The Role of Seismic Technology to Unravel the Hydrocarbon Potential of Mexican Basins

摘要

Seismic reflection technology has been widely used in Mexico to infer geological, petrophysical, and more recently, rock physics parameters of petroleum targets. First seismic refraction studies in Mexican basins were done in 1938, and the first application of seismic reflection technology occurred immediately after, in 1939. By 1966, the first common reflection point (CMP) survey was shot in Mexico. After that time, a campaign of 2D seismic studies was observed to happen in various basins, such as the Burgos, Tampico-Misantla, Veracruz, and Sureste basins. This led to the discovery of numerous oil fields in the Chiapas Tabasco fold and trust belt in onshore southern Mexico. With the support of new investments, 2D seismic coverage was extended to offshore shallow waters of the Gulf of Mexico. By 1976, the giant oil fields of the Campeche fold and thrust belt in the Campeche Sound had been discovered. 2D seismic acquisition continued for the rest of that decade with significant improvements in data quality and subsurface coverage. The first 3D seismic study in Mexico was shot in 1979, afterwards numerous 3D seismic survey were shot over onshore and offshore discovered fields. During the 1980s, 3D seismic data were used not only to infer and confirm the geometry, depth, and extent of hydrocarbon targets and fields, but also to support numerous new exploratory prospects. New acquisition methods, such as ocean bottom cable (OBC), multicomponent, long offset, and wide azimuth, in conjunction with new imaging algorithms, like reverse time migration (RTM) and controlled beam migration (CBM), and with the support of visualization and interpretation tools, resulted in more accurate subsurface models. All this led to a better understanding of basin geology, hydrocarbon potential, and associated uncertainty and risk. In those areas with high complexity, seismic imaging required special attention and effort. Amplitude extraction through the application of seismic attributes played an important role in unraveling the facies distribution to make reliable gross depositional environment maps. Needless to say, the value of seismic technology increases considerably as geological information, derived from hundreds of wells, is incorporated to build subsurface models. This has positively impacted reliability and confidence of: basin modeling, structural modeling, facies models, seal analysis and reservoir characterization. Quantitative interpretation, such as: amplitude variations with offset (AVO), seismic inversion, direct hydrocarbon indicators (DHI), and rock physics is applied to support drilling locations, both for exploration and development purposes. 3D seismic data are becoming more important in appraisal and field development, as well as in pore pressure prediction studies and shallow hazard assessment. The recent opening of the oil industry in Mexico has created numerous opportunities, both for old and new players, to improve the quality of existent 3D seismic data, and to conduct new exclusive or multi-client surveys. All that will lead to a better understanding of the remaining opportunities left in Mexican "mature" basins and to investigate the potential of frontier areas, such as those in the deepwater region of the Gulf of Mexico.