CN1243958A

CN1243958A - Method and device for measuring properties of fluid in bearing stratum

Info

Publication number: CN1243958A
Application number: CN 98116533
Authority: CN
Inventors: 邓友明
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-03
Filing date: 1998-08-03
Publication date: 2000-02-09

Abstract

An in-well measuring method for recognizing the fluid properties of bearing stratum in petroleum and geological exploration and its device are disclosed. A composite current with at least two frequencies is transmitted to the bearing stratum to be measured. The resultant signals for relative frequencies are received and compared. For the well segment with big difference in amplitude, the fluid properties of its bearing stratum is oil (gas). Otherwise, it is water. The work principle of the drive for device for implementing said method is similar to that of ground resistance meter.

Description

Properties of fluid in bearing stratum measuring method and equipment thereof

The present invention relates to a kind of equipment that is applicable to the borehole measurement method of identification properties of fluid in bearing stratum in the petroleum geology exploration exploitation and implements this method.

In the prior art, in order accurately to discern reservoir inner fluid character, there are complicated time-consuming, the defectives such as radius of investigation is too little, instrument manufacturing complexity, expense costliness of construction respectively in the general well logging of combined resistance rate, dielectric log, carbon-oxygen log and the nmr logging method of adopting, this several method.

The purpose of this invention is to provide the properties of fluid in bearing stratum new method of measuring that a kind of easy construction, radius of investigation are big, the instrument manufacturing is more simple, expense is more cheap, the measuring equipment of implementing this method is provided simultaneously.

Measuring method feature of the present invention is the recombination current that at first produces at least two kinds of frequencies by specialized equipment, behind the reservoir that this electric current input is measured, but the measuring-signal that certainly leads to respective frequencies, then by specialized equipment with signal receive, arrangement, record, signal with record compares at last, the bright properties of fluid in bearing stratum of well segment table that amplitude difference ratio is little is a water, and the bright properties of fluid in bearing stratum of well segment table that amplitude difference ratio is big is an oil (or gas).

The specialized equipment name that provides for enforcement this method is called: the properties of fluid in bearing stratum identifier.The instrument class of this equipment work principle and structure and existing Formation Resistivity Measurement seemingly, its principle of work feature is to have to tested reservoir to supply with the ability of recombination current of at least two kinds of frequencies and the ability of sorting arrangement respective frequencies measuring-signal; Its architectural feature is the selective frequency amplifier circuit with recombination current generator circuit and respective frequencies.The recombination current generator circuit can add frequency divider by high frequency signal generator and add frequency mixer and add amplifier and form, and also can add LF oscillator by high frequency oscillator and add amplifier and add the transformer mixing and form.

Further describe below in conjunction with Figure of description.

Fig. 1 is this method ground rock core experiment conclusion data plot.

Fig. 2 is that this method and prior art are used the wave mode comparison diagram.

Fig. 3 is that this method and equipment thereof are implemented achievement using method introduction figure.

With reference to Fig. 1, the operating frequency that adopts when X-axis is measurement, Y-axis is rock core electric conductivity measured value. (1) Measured value when moisture in the rock core hole, measured value when (2) are oil-containing in the rock core hole (gas). Fig. 1 shows: when When operating frequency was changed to 2KHz by 20Hz, hole saturated core measurement variation rate was far longer than the hole water-bearing rock Heart measurement variation rate, this just lays a good foundation for borehole measurement.

Analyzing its theoretical foundation should be: the existing resistance characteristic of the conduction property of reservoir has again capacitance characteristic (inductance spy The property owing to offset by capacitance characteristic, just no longer analyze), when being full of non conducting fluid (oil or gas) in its hole, The reservoir conductive characteristic is resistance characteristic and capacitance characteristic and deposits that height frequency measurement this moment difference is bigger; When the reservoir hole When being full of conductor fluid (water) in the crack, capacitance characteristic is cut down by a large amount of short circuits in the reservoir conduction property, is simple electricity Resistance conduction trend, height frequency measurement this moment difference is littler. According to above characteristic, adopt arbitrary group of height frequency electricity Stream is measured same reservoir, and observation and comparison height frequency measurement difference ratio just can reach the identification reservoir fluid The purpose of character.

With reference to Fig. 2, (3) operating current wave mode in tested stratum, using during resistivity measurement in the prior art Figure. In the instrument of all kinds of models, the normal operation frequency is 15Hz to 810Hz. The instrument that uses this wave mode be with Obtaining true formation resistivity is tidemark. (4) the recombination current composite wave that uses in tested reservoir for this method Type figure (single wave mode also can be square wave or other wave mode among the figure). Recommended frequency is low frequency 20Hz, high frequency 20KHz. On the basis of existing resistivity instrument, new energization satisfies any circuit structure of (4) institute oscilloscope-type recombination current, Can become the equipment of implementing this method after adding conventional frequency-selecting, arrangement, writing circuit. This equipment be with Obtaining the accurate low-and high-frequency measurement of reservoir difference ratio is highest goal.

Below be the easiest embodiment that is understood by the well logging colleague.

Adopt the depth of a cover Daqing oil field manufacturing and survey three side direction instrument and be the basis; Original 115Hz electric current in the downhole probe is used as low-frequency current; Adjust the electric capacity and the resistance of 810Hz oscillator, make the high-frequency signal of its output 20KHz; Adjust former 810Hz bandpass filter resistance and electric capacity, make its high-frequency signal by 20KHz; Relay J 12 and electrode A 2 lines are disconnected, and A2 connects (purpose is to allow high-frequency current and low-frequency current with walking dark side direction loop) with the A1 short circuit; Adjust the electric capacity and the resistance of frequency-selecting amplifier in the floor panel, make it pass through the 20KHz high-frequency signal.By above transformation, the shallow side direction circuit of former 810Hz has become the dark side direction circuit of 20KHz high frequency, in conjunction with the dark side direction circuit of original 115Hz low frequency, can realize that so the most basic equipment with practical value of this method has just produced.As adopt bilateral to instrument, and method for remanufacturing is similar substantially, and those of ordinary skill can both be implemented.

With reference to Fig. 3, (5) are low-frequency resistance rate actual measured value during with change in depth in the well, and (6) are alternating-current resistance rate actual measured value during with change in depth in the well.(7) its measured value amplitude difference is less when two lines are close, shows that fluid properties is a water in the reservoir rock hole; (8) its measured value amplitude difference is bigger when two line distance of separations are big, shows that fluid properties is an oil (or gas) in the reservoir rock hole.

Fig. 3 measure the achievement obtain manner and present resistivity curve obtain manner identical, so the complexity of constructing, radius of investigation size, the easily manufactured degree of instrument, the every economic and technical norms of expense size are also close with existing resistivity mode, thereby reached purpose of the present invention.

Claims

1, a kind of measuring method of in well, discerning properties of fluid in bearing stratum, it is characterized in that by the recombination current of specialized equipment at least two kinds of frequencies of tested reservoir input, receive the signal of respective frequencies again by specialized equipment, relatively the big bright properties of fluid in bearing stratum of well segment table of amplitude difference is an oil (gas), and the bright properties of fluid in bearing stratum of well segment table that the amplitude difference is little is a water.

2, a kind of specialized equipment of implementing the properties of fluid in bearing stratum measuring method, its principle of work and structure are with existing resistivity measurement instrument class seemingly, the principle of work feature is the ability that oriented tested reservoir is supplied with the recombination current ability of at least two kinds of frequencies and sorting, arrangement respective frequencies measuring-signal, and architectural feature is the selective frequency amplifier circuit with recombination current generator circuit and respective frequencies.

3, recombination current generator circuit according to claim 2 can add frequency divider by high frequency signal generator and adds frequency mixer and add amplifier and form, and also can add LF oscillator by high frequency oscillator and add amplifier and add the transformer mixing and form.