The DAR Technology is a patented technology for controlling fluids with different densities. Density is a reliable physical property to use for identifying different fluids normally present in wells, like oil, gas, water and well construction fluids.
Individual fluid control modules are designed to automatically react to fluids with different densities and control their flow by use of flotation elements that distinguish between desired and undesired fluids. For example, a water control module has a flotation element with a density somewhere between that of oil and formation water, thereby closing for water and opening for oil. The binary characteristics of the fluid control modules ensure they are either open or “closed”.
When “closed”, a small “pilot flow” remains through the fluid control module to ensure that it can continue to identify and react to the fluids flowing through it, thereby allowing it to re-open if oil comes back. This dual ICD functionality allows for an individual control of the flow rate and pressure drop in either position. The operator can also specify the limiting phase fractions of undesired fluid, at which the fluid control module shall close and re-open, respectively.
The fluid control modules are integrated in the lower horizontal well completion using an assembly developed for this purpose: the DAR Assembly. This assembly ensures correct orientation and functionality of the control modules.