Operating characteristics of downhole memory recorder

The problem of minimizing memory utilization of self-contained downhole measurement tools by discrimination between linear and nonlinear regions of measured data is described. A minimization method that performs this task is presented. A method for dynamically changing the operating characteristics of the linear discriminator to take into account the amount of remaining memory and the remaining power in the battery is presented. The linear data discriminator provides for an initial setup adjustment to compensate for expected system noise to reduce the number of data points recorded due to that measurement noise. Classical hypothesis testing is the analytical method used to implement the linear discrimination algorithm. Field use results, as well as computer simulation of the system, are presented