System and method for dynamic measurement of streaming potential in a core plug
AssigneeSaudi Arabian Oil Company
InventorsDong Kyu Cha, Subhash C. Ayirala, Ali Abdullah Al-Yousef
Life of this patent
Estimating the term…
Abstract
A system to measure a streaming potential of a core plug includes a measurement cell having a chamber to hold the core plug and an inlet fluid line connected to an inlet port of the measurement cell. A filtration device is arranged to control a salinity and ionic strength of a liquid medium received in the chamber through the inlet fluid line. The filtration device has membrane filters with different ion rejection rates and is controllable to selectively dispose each of the membrane filters in the inlet fluid line.
Claims20
A system to measure streaming potential of a core plug, the system comprising:
- a measurement cell comprising a core holder having a chamber defined therein, a first port through which the chamber can receive a liquid medium, a second port through which the liquid medium can leave the chamber, a pair of electrodes positioned to measure an electrical potential between opposing ends of the chamber;
- a first fluid line connected to the first port to provide the liquid medium to the first port;
- a second fluid line connected to the second port to receive the liquid medium from the second port;
- a filtration device having a plurality of membrane filters with different ion rejection rates, the filtration device having at least one member that is controllable to selectively dispose each of the membrane filters in the first fluid line such that a flow direction of the membrane filter that is disposed in the first fluid line is aligned with a flow direction of the first fluid line, whereby the membrane filter having the flow direction that is aligned with the flow direction of the first fluid line adjusts a salinity and an ionic strength of the liquid medium passing through the first fluid line to the first port;
- and
- an electrical circuit connected to the pair of electrodes to measure the electrical potential across the pair of electrodes.
A method of measuring a streaming potential of a core plug, the method comprising:
- supporting the core plug in a chamber that is fluidly connected to a first fluid line and a second fluid line;
- driving a liquid medium from the first fluid line, through the core plug in the chamber, to the second fluid line for a time period;
- during at least a portion of the time period:
- selecting at least one membrane filter from among a plurality of membrane filters having different ion rejection rates;
- and
- aligning a flow direction of the at least one membrane filter with a flow direction of the first fluid line, whereby the at least one membrane filter adjusts a salinity and an ionic content of the liquid medium driven through the core plug;
- and
- measuring an electrical potential across a pair of electrodes positioned in contact with the liquid medium at opposing ends of the core plug.
Dependencies are inferred from the claim text.