PIPELINE MONITORING SYSTEMS

An oil pipeline, which connects a Christmas tree at its lower end to an oil rig at its upper end, is fitted with a stainless steel tube sheathed telecommunications grade optical fiber, forming part of a distributed temperature measurement device, such as to be in thermal contact with the oil flowing along the pipeline. Also fitted to respective ones of three discrete positions on the pipeline are ultrasonic deposit thickness measurement devices, the one nearest of which to the Christmas tree is a few hundred meters downstream from a position where preliminary studies of the pipeline system have indicated that deposits are likely to form during oil production. A computer, located on the oil rig, is connected to be able to provide control over and to receive measurement signals from the temperature measurement devices and the deposit thickness measurement devices. A model of at least deposit deposition stored in the computer is revised in response to these signals. The model includes an approximation of the temperature, the pressure and the viscosity and flow patterns of the oil along the length of the pipeline and, from these parameters, an estimation of the nature and quantity or rate of deposit deposition along the length of the pipeline.