The purpose of formation evaluation is to quantify the production potential of a well using remote sensing methods. Operators want to know the size of the reservoir, the quantity of hydrocarbons in place, and the ability of the reservoir to produce hydrocarbons. The ultimate goal of formation evaluation is to decide whether it is worthwhile to complete a well, and, if so, how the well should be completed. In the end, these are business decisions that come down to economic considerations. Logging and coring, discussed in this module, are two of the main formation evaluation techniques used in the oil and gas industry. Other techniques generally consist of evaluating pressure versus time scenarios, also known as “pressure transient analysis”.