Paleomagnetic projects in Venezuela, Trinidad, Colombia, and Ecuador include many examples where Applied Paleomagnetics provided paleomagnetic services to petroleum and geotechnical companies since 1986. Our paleomagnetic projects in Venezuela, Trinidad, Colombia, and Ecuador include extensive use of our paleomagnetic core orientation service to determine natural fracture, bedding, and in situ stress orientations in oil and gas fields. In western Venezuela, our paleomagnetic projects focused on paleomagnetic core orientation in the following formations: Rio Negro, Cogollo, La Luna, Misoa, Pauji, Santa Barbara, La Rosa in the following oil fields: Lagunillas, Bachaquero, Ceuta, La Ceiba, Lagunillas, Mara, Sol, Urdaneta, Bloques I, V, IX. In eastern Venezuela, our paleomagnetic projects focused on paleomagnetic core orientation in the San Antonio, San Juan, and Vidono formations in the Boqueron, Santa Barbara, and Orocual oil fields. In Colombia, our paleomagnetic projects emphasized paleomagnetic core orientation in the Guadalupe, Mirador, and Carbonera formations in the Cano Limon and Castilla oil fields. In Trinidid, we performed paleomagnetic core orientation of geomechanical test samples in Angostura field. The goals of our paleomagnetic core orientation projects in Venezuela, Trinidad, and Colombia were paleomagnetically to orient natural fractures, induced fractures (for in situ stress), cross-beds in sands (for paleocurrent directions), and bedding in shale (for structural dip). Understanding natural fractures and in situ stress in oil reservoirs in Venezuela, Trinidad, Colombia, and Ecuador is important for determining permeability anisotropy and for planning optimum wellbore trajectories and well locations. Understanding sediment transport directions is important in oil reservoirs in Venezuela, Trinidad, Colombia, and Ecuador, because permeability anisotropy in many reservoir sands is controlled by trends of distributary channels in deltaic sands or by elongation of tidal sand bodies. Other paleomagnetic projects we conducted in Venezuela, Trinidad, Colombia, and Ecuador were focused on understanding the tectonic history and changes in magnetic properties associated with hydrocarbon migration in oil reservoirs, especially along strike-slip faults in Lake Maracaibo, like the Icotea, VLE, and Pueblo Viejo faults. In Ecuador, we measured magnetic susceptibility and other magnetic properties of core samples from the Ximena gold mining area.