Flow measurements in an oil reservoir

Abstract

The present invention provides for a down-well fluid measuring arrangement, and related methods, having at least one surface defining part of a fluid path, the at least one surface having first and second ports each arranged to deliver fluid to a single pressure gauge ( 28 ), one of the ports being provided in the region of an obstruction formation ( 30 ) provided in the fluid path, the arrangement further including switch means ( 34 ) arranged to change the port delivering fluid to the gauge so as to allow for determination of a pressure difference of the fluid at the said ports and a third port located either upstream or downstream of the first port delivering fluid the gauge to allow of determination of a pressure difference and hence volume fraction.

1 . A down-well fluid measuring arrangement having at least one surface defining part of a fluid path, the at least one surface having first and second ports each arranged to deliver fluid to a single pressure gauge, one of the ports being provided in the region of an obstruction formation provided in the fluid path, the arrangement further including switch means arranged to change the port delivering fluid to the gauge so as to allow for determination of a pressure difference of the fluid at the said ports. 
     
     
         2 . An arrangement as claimed in  claim 1  and comprising an annular arrangement. 
     
     
         3 . An arrangement as claimed in  claim 2  and comprising a cylindrical arrangement having the parts provided on the inner or outer surface of a cylindrical section. 
     
     
         4 . An arrangement as claimed in  claim 1  and comprising an element of production tubing to be employed as one functional element of a production tubing string. 
     
     
         5 . An arrangement as claimed in  claim 1 , wherein the pressure gauge comprises a combined pressure temperature gauge. 
     
     
         6 . An arrangement as claimed in  claim 1 , wherein three ports are provided each of which is arranged to be switched, in turn, to the pressure gauge. 
     
     
         7 . An arrangement as claimed in  claim 1  wherein a separate switch valve arrangement is provided with each port and which feed respective conduits leading to a connector block or delivering fluid to the gauge. 
     
     
         8 . An arrangement as claimed in  claim 1  and including conduits from each of the ports leading to a multi-way valve switch arranged to be controlled to determine which of the ports delivers fluid to the gauge. 
     
     
         9 . An arrangement as claimed in  claim 7 , wherein the switch(es) is/are arranged to be controlled in a cyclical manner to allow for repeated delivery of fluid from each of the ports in a repeated cyclical manner. 
     
     
         10 . An arrangement as claimed in  claim 1 , including three ports wherein a first and second of the ports are located in a relatively close manner, with the third port being remote therefrom. 
     
     
         11 . An arrangement as claimed in  claim 10 , wherein one of the first and second ports is provided at the throat of or just after the obstruction formation, and the other at the inlet thereof. 
     
     
         12 . An arrangement as claimed in  claim 10 , comprises an elongate tubing section with the said third port being spaced in the order of one to two metres from the obstruction formation. 
     
     
         13 . An arrangement as claimed in  claim 1  wherein the obstruction formation is arranged to exhibit a degree of flexibility and resilience. 
     
     
         14 . An arrangement as claimed in  claim 1  and further including means for facilitating communication of data from the pressure gauge in a wired, or wireless, manner. 
     
     
         15 . An arrangement as claimed in  claim 1  and including packer means provided interspersed on an outer surface of the arrangement. 
     
     
         16 . An arrangement as in  claim 1 , further comprising a down-well tubing string. 
     
     
         17 . An arrangement as defined in  claim 1 , wherein the obstruction formation comprises a venturi or orifice formation. 
     
     
         18 . (canceled) 
     
     
         19 . A method of down-well fluid measurement, including introducing fluid to first and second parts of a measuring arrangement switching in a cylindrical manner the parts into, and out of, fluid communication with a single pressure gauge to obtain pressure readings at the parts by means of the said gauge. 
     
     
         20 . A down-well two-phase fluid sensor device arranged to be exposed to fluid in an open hole section of a producing well and having a sensor element arranged to be exposed to the fluid and to determine the volume fraction of the two phases in the fluid, the sensor element also being located so as to sense fluid external of the device and in the generally annular space between reservoir rock and the outer device surface. 
     
     
         21 . A device as claimed in  claim 20  and including a flow rate detector. 
     
     
         22 . A device as claimed in  claim 21  wherein the flow rate detector comprises a pressure-drop detector employing an obstruction formation. 
     
     
         23 . A device as claimed in  claim 22  wherein the obstruction formation comprises a flexible and resilient member arranged to allow passage of down-well tools. 
     
     
         24 . A device as claimed in  claim 20 , wherein the sensor comprises one of a capacitive sensor or resistive sensor. 
     
     
         25 . A device as claimed in  claim 20 , and packer means provided interspersed between sensor elements including means for facilitating communication of output derived from the sensor can be provided and such communication means can comprise wired or wireless connection means. 
     
     
         26 . (canceled) 
     
     
         27 . A down-hole production tubing string comprising a fluid sensor device as in  claim 20 .