CN105626039A - Method for preprocessing related flow data in production logging - Google Patents

Abstract

The invention provides a method for preprocessing related flow data in production logging. The method comprises: setting a depth curve DEPTH, a gamma ray curve GR and a time curve TIME for related flow data; carrying out FIR (Far Infrared Rays) filtering, and carrying out second-order derivation on the filtered gamma ray curve GR; when a second derivative is smaller than 0, obtaining local peak values of the gamma ray curve GR; comparing the local peak value with a system preset threshold, filtering out the local peak values smaller than the threshold, and retaining the local peak values greater than the threshold; writing false depths, true depths and time values of corresponding local depths of the gamma ray curve GR into a table together, and calculating fluid velocities; drawing a curve by point values of the calculated fluid velocities. The method has the core how to accurately identify the local maximum value of the GR curve by an algorithm; the processing flow is simple and convenient to operate; automatic identification accuracy is high; a processing effect is good; the method has a certain popularization and application value.

Description

A kind of method of production logging correlative flow data prediction

Technical field

The invention belongs to oil development and engineering field, be a kind of in production logging injection profile is explained, the method for correlative flow data prediction.

Background technology

Along with the development of production logging technology, correlative flow technology is more and more applied in the explanation of water injection profile. During correlative flow is applicable to, Low-flow Wells, be typically in water injection well and use, use at producing well and resolution can be made to decline due to variations in flow patterns. In the well that turbine flowmeter can not be used to measure, it is generally adopted correlation flowmeters. Correlation flowmeters determine that the method for flow is tachometric method in the wellbore. Measure and install instruments according to hole condition, instrument is parked between two perforation layers in pit shaft and sprays tracer, then measuring tracer in two somes transmission required time, refer generally between two detectors or ejector is to the time between detector, what thereby determine that each interpretation layer looks flow velocity. For producing well, spray site near the bottom of perforation layer interlayer, for injecting well, then should select the top of interlayer. According to metering system, tachometric method includes two kinds of methods, and one is static measurement method; Another kind is tracking method.

For gamma-ray detector, it is change owing to spraying the time of tracer, therefore accurately determines that injection tracer arrives the time popped one's head in comparatively difficult, be therefore generally adopted continuous method for tracing. In this case, in an interlayer, at least three times to be carried out and measure. Owing to while measuring, spike bridging plug is also flowing, it is therefore necessary to ensure there is the spike slug that sufficiently high flow-speed measurement is complete. If it find that primary displacement is relatively big, then should accelerate to test the speed, otherwise then reduce and test the speed. The computational methods of flow velocity are

$Va=\frac{\mathrm{\Δ}H}{\mathrm{\Δ}t}$

In formula, �� H measures the distance (depth difference of peak value) of tracer slug displacement for twice;

�� t is the time needed for slug displacement;

The local maximum finding exactly GR curve that correlative flow pretreatment is done, namely crest, the then pseudo-degree of depth according to crest, find true depth that Depth curve is corresponding and time corresponding to Time curve, then just can calculate the flow velocity of 2.

Summary of the invention

It is an object of the invention to there is again, by automatic program identification GR curve local maxima, manual interaction pickup, the problem wasted time and energy for currently without good, find a kind of program of can passing through and automatically identify local maximum with the corresponding threshold value of setting and then calculate the correlative flow preprocess method of rate curve. The present invention passes through automatic program identification GR curve local maxima, according to the pseudo-degree of depth that local maximum is corresponding, obtains corresponding true depth, time, thus calculating flow velocity, the present invention is easy and simple to handle, automatically identifies that accuracy is high, has certain engineer applied and is worth.

It is an object of the invention to be realized by following technical proposals.

A kind of method of production logging correlative flow data prediction, comprises the following steps:

Step 1, to the production logging correlative flow data adopting single probe tracking method to measure, arranges depth curve DEPTH, gamma curve GR and time graph TIME;

Step 2, carries out FIR filtering to gamma curve GR, removes burr and interference;

Step 3, carries out second order derivation to filtered gamma curve GR:

GR "=GR [i+1]+GR [i-1]-2*GR [i]

In formula, i represents current gamma curve data point, and i-1 represents previous data point, and i+1 is later data point; GR " for the second dervative of gamma curve;

Step 4, when second dervative is less than 0, is the position of gamma curve GR local maximum, i.e. gamma curve GR local peaking;

Step 5, by gamma curve GR local peaking with systemic presupposition threshold ratio relatively, less than threshold value, is then not considered as gamma curve GR local maximum, filters out; More than threshold value, then it it is required gamma curve GR local maximum;

Step 6, the gamma curve GR required for step 5 being obtained the locally corresponding pseudo-degree of depth of the degree of depth, true depth and time value write in form in the lump, calculate fluid velocity;

Step 7, is depicted as curve by calculated fluid velocity point value.

Further, in step 2, adopting 31 limited long band bandpass filters to carry out FIR filtering gamma curve GR, set GR discretization plot against time and adopt 4us, frequency filtering is 1-8khz.

Further, in step 5, when program starts, read gamma curve GR all values, therefrom count 1/10th of gamma curve GR maximum threshold values by default.

Further, in step 6, fluid operator speed that corresponding for all gamma curve GR local pseudo-degree of depth of the degree of depth, true depth and time value write form are fallen into a trap, obtained by following formula:

V=60* (Depth [i-1]-Depth [i])/(Time [i-1]-Time [i])

Wherein, V represents the mean flow rate of Depth [i-1] to degree of depth Depth [i], Depth [i-1] is the i-th-1 corresponding true depth, Depth [i] be i-th to true depth, Time [i-1] is the i-th-1 corresponding time, and Time [i] is i-th corresponding time.

Further, in step 7, calculated fluid velocity point value is depicted as curve, is accomplished by:

The fluid velocity of Depth1, Depth2 respectively V_depth1, V_depth2, then the degree of depth is V_depthFluid velocity be:

V_depth=V_depth2+(Depth-Depth2)*(V_depth1-V_depth2)/(Depth1-Depth2)��

Relative to prior art, the beneficial effects of the present invention is:

A kind of method that the invention provides production logging correlative flow data prediction. How its core is accurately identifying GR curve local maxima by algorithm, the present invention adopts and first GR curve is carried out FIR filtering, then to curve secondary derivation, it is local maximum less than 0 by second derivative, local maximum is compared with setting threshold value, less than filter out, then according to the corresponding true depth of local maximum position acquisition, time, thus calculating rate curve. This handling process possesses novelty. Execute-in-place is easy, and treatment effect is better, possesses certain application value.

Accompanying drawing explanation

Fig. 1 is handling process schematic diagram.

Fig. 2 is that parameter arranges dialog box.

Fig. 3 is recognition effect figure, the red local maximum representing identification.

Fig. 4 is the curve data that the local maximum stored in a tabular form is corresponding.

Fig. 5 is for calculating rate curve dialog box.

Fig. 6 is the rate curve design sketch calculated.

Detailed description of the invention

Below in conjunction with particularly relevant flow rate log data, the specific embodiment of the present invention is illustrated.

As it is shown in figure 1, the method for a kind of production logging correlative flow data prediction of the present invention, comprise the steps:

Step 1, relevant parameter is set, as shown in Figure 2, to the production logging correlative flow data adopting single probe tracking method to measure, the depth curve DEPTH of input, gamma curve GR, time graph TIME are set, arranging range coefficient 1 is the crest taken, and it is 603 that Automatic Program calculates an input threshold size. Setting direction is for lifting up well logging, then program statistical computation lifts up the maximum in direction. The degree of depth is oriented to deeply, and when what the amplitude of referring to took is not crest or trough, but when crest is multiplied by range coefficient, what value at this moment took is the first half or the latter half.

Step 2, click is determined, Automatic Program processes. The flow process of program inter-process flow chart as shown in Figure 1, first carries out GR is adopted FIR filtering, and FIR filtering adopts 31 limited long band bandpass filters, and the setting GR time adopts 4us, and frequency filtering is 1-8khz.

Step 3, the GR discretization curve to filtering, carry out second order derivation:

GR "=GR [i+1]+GR [i-1]-2*GR [i]

In formula, i represents current gamma curve data point, and i-1 represents previous data point, and i+1 is later data point; GR " for the second dervative of gamma curve.

Step 4, when second dervative is less than 0, it is simply that the position of local maximum, namely local GR peak value.

Step 5, locally with threshold ratio relatively, less than threshold value, then will be not considered as local maximum, filter out by GR peak value; More than threshold value, then it it is required gamma curve GR local maximum;

Wherein, when program starts, read gamma curve GR all values, therefrom count 1/10th of gamma curve GR maximum threshold values by default.

Step 6, in the GR value of all local maximum correspondence degree of depth, the pseudo-degree of depth, true depth, time value write form, will calculate fluid velocity:

V=60* (Depth [i-1]-Depth [i])/(Time [i-1]-Time [i])

Wherein, V represents the mean flow rate of Depth [i-1] to degree of depth Depth [i], Depth [i-1] is the i-th-1 corresponding true depth, Depth [i] be i-th to true depth, Time [i-1] is the i-th-1 corresponding time, and Time [i] is i-th corresponding time.

Step 7, is depicted as curve by calculated fluid velocity point value, is accomplished by:

The fluid velocity of Depth1, Depth2 respectively V_depth1, V_depth2, then the degree of depth is V_depthFluid velocity be:

V_depth=V_depth2+(Depth-Depth2)*(V_depth1-V_depth2)/(Depth1-Depth2)��

The form such as Fig. 4 generated, the design sketch of peak value automatic Picking such as Fig. 3, the visualization that crest correspondence horizontal line part is Fig. 4 form shows, corresponding is the position of GR peak value, right side graph is track depth curve, corresponding is real depth value, and calculating is the peak value lifting up direction, and corresponding track depth curve is the part that up degree of depth increases. Can be seen that identification peak is very accurate, it does not have omit.

According to the form preserved, calculate rate curve and resultant curve; Fig. 5, for arranging dialog box accordingly, selects the TVAU01 form generated, clicks " transformation curve ", then generate corresponding curve, and method is to the speed form generated, and carries out linear difference, formation speed curve. The speed effect figure generated is as shown in Figure 6.

The embodiment above embodiment of the present invention provided is described in detail, principle and the embodiment of the embodiment of the present invention are set forth by specific case used herein, and the explanation of above example is only applicable to help to understand the principle of the embodiment of the present invention; Simultaneously for one of ordinary skill in the art, according to the embodiment of the present invention, all will change in detailed description of the invention and range of application, in sum, this specification content should not be construed as limitation of the present invention.

Claims (5)

1. the method for a production logging correlative flow data prediction, it is characterised in that comprise the following steps:

Step 1, to the production logging correlative flow data adopting single probe tracking method to measure, arranges depth curve DEPTH, gamma curve GR and time graph TIME;

Step 2, carries out FIR filtering to gamma curve GR, removes burr and interference;

Step 3, carries out second order derivation to filtered gamma curve GR:

GR "=GR [i+1]+GR [i-1]-2*GR [i]

In formula, i represents current gamma curve data point, and i-1 represents previous data point, and i+1 is later data point; GR " for the second dervative of gamma curve;

Step 4, when second dervative is less than 0, is the position of gamma curve GR local maximum, i.e. gamma curve GR local peaking;

Step 5, by gamma curve GR local peaking with systemic presupposition threshold ratio relatively, less than threshold value, is then not considered as gamma curve GR local maximum, filters out; More than threshold value, then it it is required gamma curve GR local maximum;

Step 6, the gamma curve GR required for step 5 being obtained the locally corresponding pseudo-degree of depth of the degree of depth, true depth and time value write in form in the lump, calculate fluid velocity;

Step 7, is depicted as curve by calculated fluid velocity point value.

2. method according to claim 1, it is characterised in that in step 2, adopts 31 limited long band bandpass filters to carry out FIR filtering gamma curve GR, sets GR discretization plot against time and adopts 4us, and frequency filtering is 1-8khz.

3. method according to claim 1, it is characterised in that in step 5, when program starts, reads gamma curve GR all values, therefrom counts 1/10th of gamma curve GR maximum threshold values by default.

4. method according to claim 1, it is characterised in that in step 6, fluid operator speed that corresponding for all gamma curve GR local pseudo-degree of depth of the degree of depth, true depth and time value write form are fallen into a trap, obtained by following formula:

V=60* (Depth [i-1]-Depth [i])/(Time [i-1]-Time [i])

Wherein, V represents the mean flow rate of Depth [i-1] to degree of depth Depth [i], Depth [i-1] is the i-th-1 corresponding true depth, Depth [i] be i-th to true depth, Time [i-1] is the i-th-1 corresponding time, and Time [i] is i-th corresponding time.

5. method according to claim 1 or 5, it is characterised in that in step 7, calculated fluid velocity point value is depicted as curve, is accomplished by:

The fluid velocity of Depth1, Depth2 respectively V_depth1, V_depth2, then the degree of depth is V_depthFluid velocity be:

V_depth=V_depth2+(Depth-Depth2)*(V_depth1-V_depth2)/(Depth1-Depth2)��