In-situ Stress : The stresses on the formation imposed by the overlying overburden and tectonic forces. The stresses are at least partially offset by the fluids in the pores of the formation
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}