1. A method for measuring technical maturity index (TMI) for oilfield operations of an oilfield, the oilfield having a subterranean formation with geological structures and reservoirs therein, comprising: sending, to at least one user associated with an oilfield operation, an assessment comprising a plurality of iteratively defined capabilities for performing the oilfield operation for a wellsite, wherein the plurality of iteratively defined capabilities comprise a first capability to perform a task of the oilfield operation for the wellsite, a second capability to practice the first capability in real-time, a third capability to practice the second capability from a remote location from the wellsite, a fourth capability to practice the third capability for performing diagnostics of the oilfield operation for the wellsite, and a fifth capability to practice the fourth capability by multiple users, and wherein the plurality of iteratively defined capabilities comprise data acquisition and transmission from the wellsite, monitoring activities as they happen at the wellsite, surveillance with early warning capability, diagnostics and analysis, extended team and expertise beyond the wellsite, remote actuation and operation, model-centric diagnostics, global collaboration, model-based corrective action, and automation and autonomous action; receiving, in response to the assessment for the oilfield operation, a plurality of responses comprising a first level of adoption, a second level of adoption, a third level of adoption, and a fourth level of adoption, wherein the first level of adoption represents how frequent the first capability is practiced for the oilfield operation, the second level of adoption represents how frequent the second capability is practiced for the oilfield operation, the third level of adoption represents how frequent the third capability is practiced for the oilfield operation, and the fourth level of adoption represents how frequent the fourth capability is practiced for the oilfield operation; comparing a level of adoption corresponding to one of the plurality of iteratively defined capabilities with a corresponding goal level of adoption for the one of the plurality of iteratively defined capabilities; calculating, by a computer processor, a plurality of technology maturity scores by calculating a weighted summation for each adoption level in the plurality of responses; aggregating, by the computer processor, the first level of adoption, the second level of adoption, the third level of adoption, and the fourth level of adoption into a TMI for the oilfield operation using the plurality of responses, wherein the TMI is an average of the plurality of technology maturity scores and represents a single measure of adoption of the plurality of iteratively defined capabilities for the oilfield operation; and presenting the TMI for the oilfield operation.