A Method for Formation Temperature Estimation Using Wireline Formation Tester Measurements

摘要

Production data show that early estimates of formation temperature are often inaccurate. Fluids arriving at production facilities can have temperatures that are significantly different from the expected values; the difference is in part because of inaccuracy in heat-loss estimates. Moreover, the initial formation temperature estimate may also be significantly in error. The pitfalls in formation temperature predictions have great impact on the effectiveness of flow assurance, well completion, and production facility design and performance. Usually formation temperature is estimated from openhole and cased hole logs, slickline temperature measurements, or stabilized wellbore temperature measurement during sampling and testing operations. A new method for determining formation temperature from wireline formation tester temperature measurements has been developed. Rather than being simulated, the thermal history covering the formation cooling phase is represented by a single unknown parameter-either the average wellbore temperature opposite the interval of production or the average heat flux from the wellbore into the formation. One of these parameters and the initial formation temperature are the only two unknowns to be determined from the temperature measurement data obtained during fluid production phase by wireline formation tester. An inversion technique has been proposed for the formation temperature estimation based on the simplification of the thermal history simulation and the dimensional analysis of the forward problem.