TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractA number of industry sources have identified the need to improve overall productivity of subsea wells through the application of monitoring and control systems in the wellbore and on the seabed. To achieve this goal, two elements must be mastered: information and measurements of key attributes of the well/reservoir productivity, and a means to change and command the process, preferably through remote-controlled devices rather than traditional well intervention.With the advent of intelligent wells, the second element has been addressed through a variety of process control devices used at different points in the wellbore and on the seabed. However, the growth of this process was limited by the absence of effective information gathering and data transmission systems in subsea wells, which remained underdeveloped compared to other subsea hardware. This resulted in systematic information bottlenecking caused by poor connectivity between the wellbore and the rest of the subsea infrastructure.The paper introduces a complementary surveillance system that works with existing subsea devices and highlights its role in gathering and transmitting well and subsea data reliably and in sufficient time needed to maintain optimal production. In particular, the system targets high data traffic areas in order to de-bottleneck the subsea transmission systems and provides wellbore monitoring and inflow quantification. A continuous data highway is now available to both wellbore and subseabased measurements, leading to improved monitoring and control of the entire subsea system.The applications and benefits of the system are demonstrated through a case study. The study discusses the role of the surveillance system in bringing the productivity index of subsea wells to be in par with the platform wells. It also demonstrates the need to rethink the flow assurance process as increasing number of distributed seabed measurements become available to the subsea industry and tieback distances increase to make the best use of expensive host facilities. IntroductionLooking at history. The first subsea Christmas tree was installed in 1961. In the following 37 years, the industry installed 1,000 subsea wells. In the coming 5 years, well over 1,000 will be commissioned; we are in a period of exponential growth, limited mainly by industry capacity. Total subsea capital expenditures during next 5 years will increase from US$34 billion to more than US$48 billion. The majority of this spending will be in the North Sea and the deepwater Golden Triangle: Gulf of Mexico, Brazil, and West Africa.With field productivity and process optimization continuing to drive the oilfield towards lowering the risk of subsea developments and enhancing production, it is time to embrace the pivotal role of real-time information to achieving these goals.We believe the answer to increased subsea productivity is real-time data combined with scalable, integrated, pore-toprocess systems. Data-rich solutions offer a better under...

The Paleogene has been shown to contain very large reserves. The characteristics of these reserves however present some unique challenges for operators in producing them in the same economic fashion as other plays within the Gulf of Mexico. Artificial lift in the form of downhole electric submersible pumps (ESPs) or subsea mudline boosting pumps are being sought out to improve the recoverables and overall economics of Paleogene field developments.Small improvements in recovery factor can have a significant impact on the economics given the large size of these reservoirs. Many variables come into play that can impact the overall economic performance of a field development using pumps as a means of increasing recoverables. Downhole ESPs when used in combination with mudline boosting pumps have the potential for delivering the best recovery factors, however poor reliability performance and high intervention costs associated with the use of ESPs in subsea wells can negate the value of those recovery gains. Mudline boosting pumps by comparison, have lower intervention costs, and are generally accepted as having better reliability performance over downhole ESPs.A production performance analysis was performed for a number of configurations for ESP and mudline pumps for Greenfield developments to determine the improvement in recoverables. An economic performance evaluation was then conducted, comparing the value of the increased recoverables against costs for the hardware, the installation, annual operational costs, and intervention and maintenance costs over a 30 year field life of a Paleogene reservoir.

With increased focus on integrity management to maximize uptime and output, asset surveillance and integrity management are increasingly becoming core elements of subsea field developments. Condition and Performance Monitoring (CPM) provides critical real-time data to the operator which can prevent unplanned shutdowns saving millions of dollars in lost production and ensuring system integrity. Today, subsea pumps, boosting and compression systems are expected to function properly for 30 years under demanding operating conditions. However, the subsea industry has historically had limited advanced feedback on the mechanical fitness, electrical condition and operating performance of subsea rotating machinery in contrast with the advances made in condition monitoring systems commonplace now in automobiles. Subsea pumping systems are now available with a comprehensive top down approach to predicting equipment failure from a modal analysis. Advanced instrumentation, such as vibration sensors, are now available and designed specifically to monitor equipment condition and not simply for operational control of the pump system.