RIASSUNTO
Abstract
Daqing oilfield has entered the late period of extra high water production. With the development of horizontal well technology, coning of injected water is one of the most important production problems in the Daqing oilfield. The water cut of many wells in old depleted areas is more than 80%, and still rising. With the use of horizontal well technology in depleted areas, the problem will continue. An adjustable water system or smart well (intelligent completion) technology is urgently needed to solve the practical production problems in this oilfield.
This article first identifies the smart well (intelligent completion) technology, and the major companies using it. Secondly, the paper shows the development of smart well technology in China, the reason why we use smart well technology in the Daqing oilfield, the adjustable water cut system in the Daqing oilfield, and the application of smart well technology in the Daqing oilfield. Finally, a smart well is introduced, and some of advanced downhole devices and the prospects for their application in the Daqing oilfield are detailed.
Introduction
An intelligent completion can be defined as ""a completion system capable of collecting, transmitting, and analyzing completion, reservoir, and production data, and taking action to better control well and production processes.??[1] It should be noted that, the current smart well technology does not refer to automatic self-control or self-optimization, but relies on the artificial interface to initiate commands to the well. The remote monitoring system is a combination of downhole sensors and a calculation station on the surface. This system has the capacity of collecting downhole data without conventional intervention in the well, and sends the data to the calculation station for analysis. The remote control system is a combination of downhole valves and a control system on the surface. Command instructions are transmitted from the surface to downhole to alter the position or status of one or more flow-control components.[2]
Since 1997, when the first smart well was installed in Saga Snorre TLP North Sea (Norway), smart well technology has been used in many kinds of production wells all over the world, including off-shore wells, vertical conventional wells, horizontal wells, and branched wells. By 2007, more than 300 smart wells had been installed all over the world; by 2009, the number had increased to around 1400.[3]
Major smart well companies
Some companies have developed various smart well technologies. The InCharge®(TM) and InForce® technologies of Baker Oil Tools, have the capabilities of data acquisition and flow management, and can monitor real-time measurements of downhole pressure, temperature, and flow rate without expensive workover operation. WellDynamics is a joint venture between Halliburton and Shell for researching and developing smart well technology. They have developed a smart well technology including a surface control system, downhole control system and downhole tools, which can provide 100 statuses.[4] Schlumberger's reservoir monitoring and controlling system combines reservoir monitoring and stratified flow control. Its calibration system provides 6-11 statuses. The simple Intelligent TM system of Weatherford combines fiber sensing technology and flow control systems to adjust the reservoir inflow profile initially to improve recovery rate, optimize production performance, and decrease operating cost.[5]