Method for autonomous control of a chemical injection systems for oil and gas wells
US8555914B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 2, 2013 |
| Grant date | Oct 15, 2013 |
| Priority date | — |
| Expiry date | Jan 2, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7761
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A control program for a positive displacement metering system measures the time required for the travel of a free piston in a cylinder of known volume to determine an average flow rate during a full stroke of the piston. The system may also measure and record the inlet and outlet pressures or the differential pressure between the fluid inlet and outlet. The control program positions a four-way valve which may function as an adjustable metering orifice in response to the measured average flow rate and/or changes in the inlet and outlet pressures to achieve the desired flow rate. At the end of each stroke, the four-way valve is repositioned to reverse fluid flow through the metering cylinder. The system may revise the valve position settings for both forward and reverse strokes based on the measured time required for a full stroke at a certain valve position. In this way, the system automatically and iteratively compensates for changes in fluid properties and fluid pressure. A cleaning cycle which progressively opens the valve stepwise and may culminate in full open valve travel in both fluid flow directions is provided in the event of an obstruction of the valve orifice.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.