Petrom operates mature offshore oil and gas fields on the continental shelf in the Black Sea in Romania. These fields were discovered in the late 1970s and early 1980s in sandstone reservoirs and have average well and water depths of 1,700 m and 50 m respectively. Over the past 3 years, electrical submersible pumps (ESPs) have been installed in five wells resulting in production increases.

The paper reviews the ESP completion designs and focuses on the impact of real-time data on the run lives and uptimes achieved over the past 3 years. To analyze the well performance, a new technique based on the ESP torque equilibrium equation between the pump and motor was used to reconstruct a continuous rate versus time profile using real-time data.

The authors explain how the technique is valid in both transient and steady state conditions and therefore calculates the instantaneous flow rate at any time where real-time data is available. This continuous “rate log” enabled a superposition technique to be used to monitor drainage area and average reservoir pressure. It also enabled confirmation of the relation between motor temperature and well rate, and observation of the effect of high GVF through the ESP.