阅读说明：本技术 一种井震标定方法 (Well-seismic calibration method ) 是由 吴吉忠 柳波 赵小青 贾善坡 石颖 王维红 于 2019-10-13 设计创作，主要内容包括：本发明涉及的是一种井震标定方法,它包括:一、地震数据与测井数据准备；二、基于地震解释方案选取顶底标准层；三、顶部标准层标定与质控；四、底部标准层标定与质控；五、基于顶底标准层标定结果建立速度场；六、生成合成地震记录,开展井震层间小层标定。本发明以顶底参考层为约束,层间采用声波速度代替声波转换合成地震记录速度,利用平均速度拟合和趋势面去低频效应等手段消除空间误差,获得顶底及标准层间精确速度,本发明能够弥补井信息与地震数据存在时间和波形上不匹配问题,减小横向非均质性对井标定速度外推的影响,对油气资源勘探具有重要应用价值。(The invention relates to a well-seismic calibration method, which comprises the steps of firstly, preparing seismic data and logging data; secondly, selecting a top and bottom standard layer based on the seismic interpretation scheme; thirdly, calibrating and controlling the top standard layer; fourthly, calibrating and controlling the quality of the bottom standard layer; fifthly, establishing a speed field based on the calibration result of the top and bottom standard layers; and sixthly, generating a synthetic seismic record and carrying out interlayer calibration of the well seismic. The method takes the top and bottom reference layers as constraint, adopts sound wave velocity to replace sound wave conversion to synthesize the seismic recording velocity between layers, eliminates space errors by means of average velocity fitting, trend surface low frequency effect removal and the like, and obtains top and bottom and standard interlayer precise velocity.)

1. A well-seismic calibration method is characterized by comprising the following steps:

preparing seismic imaging data, logging interpretation data, seismic interpretation standard horizon data and logging interpretation standard horizon data according to the required work area range and the logging number;

selecting a top standard layer and a bottom standard layer based on the seismic interpretation scheme, and selecting stratums with strong continuity of in-phase axes and stable sedimentation characteristics from the interpretation scheme as the top standard layer and the bottom standard layer respectively;

step three, calibrating and controlling the top standard layer:

a, performing linear fitting on all acoustic logging speed curves in a work area, and solving a fitting speed value v of each well at the top standard layer position according to the fitting curves;

b, according to the fitting speed value, a time value t1 of each well at the position of the top standard layer is calculated by using a conventional time-depth conversion method, a difference value t3 exists between the time value and the seismic interpretation time t2 of the top standard layer, namely t2-t1= t3, a trend surface of all the difference values in the work area is calculated by using a least square method, and the numerical value on the trend surface is recorded as t4;

c, correcting t1 in the step b by using the value t4 of the trend surface, wherein the time value of each well at the position of the top standard layer after correction is t5= t1+ t4;

d, knowing that the drilling platform and the seismic data reference surface have static correction time difference t6, performing residual time difference correction on t5 in the step c to obtain a final calibration time value t7= t5+ t6 of the position of the top standard layer of each well;

step four, bottom standard layer calibration and quality control:

(1) leveling the top standard layer, taking the leveled top standard layer as a time starting zero point of speed fitting, performing linear fitting on the acoustic logging speeds between all top and bottom layers in the work area, and calculating a fitting speed value w of each well at the position of the bottom standard layer according to a fitting curve;

(2) according to the fitting speed value, a time value t11 of each well at the position of the bottom standard layer is obtained by using a conventional time-depth conversion method, a difference value t33 exists between the time value and the seismic interpretation time t22 of the bottom standard layer, namely t22-t11= t33, a trend surface of all the difference values in the work area is obtained by using a least square method, and the value on the trend surface is recorded as t 44;

(3) using the value t44 of the trend surface to correct t11 in the step (2), wherein the time value of each well at the bottom standard layer position after correction is t55= t11+ t 44;

establishing a speed field based on the calibration result of the top and bottom standard layers;

and step six, generating a synthetic seismic record based on the velocity field in the step five and a conventional time-depth conversion method, and carrying out interlayer calibration of the well seismic by using the synthetic seismic record.

2. The well-seismic calibration method of claim 1, wherein: the fifth step is specifically as follows:

a, calculating a difference value between a fitting speed value v corresponding to each well in a top standard layer and a speed of the standard layer, calculating a trend surface of the difference values corresponding to all wells in a work area by using a least square method, and recording a numerical value on the trend surface as vv;

b, correcting the fitting speed v corresponding to the top standard layer by using the numerical value vv on the trend surface to obtain the corrected top standard layer speed v1;

c, calculating the difference value between the fitting speed value w corresponding to each well in the bottom standard layer and the speed of the standard layer, calculating the trend surface of the difference values corresponding to all wells in the work area by using a least square method, and recording the numerical value on the trend surface as ww;

d, correcting the fitting speed w corresponding to the bottom standard layer by using the numerical value ww on the trend surface to obtain a corrected bottom standard layer speed w1;

and e, establishing a velocity field between the top standard layer and the bottom standard layer by using v1 and w1 and adopting a three-dimensional interpolation smoothing method.

The technical field is as follows:

the invention relates to the technical field of seismic data interpretation in seismic exploration, in particular to a well seismic calibration method.

Background art:

at present, the joint construction and interpretation and reservoir prediction by using seismic and logging data become the indispensable choice for fine reservoir description, but the longitudinal scale of the logging data is depth, the seismic profile is time scale, and the two data description modes are different, so that the two data cannot be directly applied in a combined manner, and therefore, the well seismic calibration between the logging data and the seismic data must be firstly carried out for developing the fine reservoir description.

The existing well-seismic calibration method is calibrated based on the correlation between synthetic seismic records and well-side seismic trace waveforms, and mainly has two problems, namely, the difference between well information and seismic data in time and waveform exists, the well logging data are measured in a depth domain, the velocity is the well-side vertical velocity, the seismic data are measured in a time domain, and the velocity is the velocity of a root-mean-square conversion layer with an incidence angle, so that a closing time error exists between the well information after time-depth conversion and ground seismic data, and the well-seismic calibration precision is not high. Secondly, the stratum lateral heterogeneity is strong, the well calibration information is difficult to extrapolate, the calibration precision of the well position is high, but when the stratum lateral heterogeneity is strong, the calibration precision of the well-free position can not be reliably guaranteed when the well calibration information is extrapolated.

The invention content is as follows:

the invention aims to provide a well-seismic calibration method which is used for solving the problem that the existing well-seismic calibration method is low in precision.

The technical scheme adopted by the invention for solving the technical problems is as follows: the well-seismic calibration method comprises the following steps:

preparing seismic imaging data, logging interpretation data, seismic interpretation standard horizon data and logging interpretation standard horizon data according to the required work area range and the logging number;

selecting a top standard layer and a bottom standard layer based on the seismic interpretation scheme, and selecting stratums with strong continuity of in-phase axes and stable sedimentation characteristics from the interpretation scheme as the top standard layer and the bottom standard layer respectively;

step three, calibrating and controlling the top standard layer:

a, performing linear fitting on all acoustic logging speed curves in a work area, and solving a fitting speed value v of each well at the top standard layer position according to the fitting curves;

b, according to the fitting speed value, a time value t1 of each well at the position of the top standard layer is calculated by using a conventional time-depth conversion method, a difference value t3 exists between the time value and the seismic interpretation time t2 of the top standard layer, namely t2-t1= t3, a trend surface of all the difference values in the work area is calculated by using a least square method, and the numerical value on the trend surface is recorded as t4;

c, correcting t1 in the step b by using the value t4 of the trend surface, wherein the time value of each well at the position of the top standard layer after correction is t5= t1+ t4;

d, knowing that the drilling platform and the seismic data reference surface have static correction time difference t6, performing residual time difference correction on t5 in the step c to obtain a final calibration time value t7= t5+ t6 of the position of the top standard layer of each well;

step four, bottom standard layer calibration and quality control:

(1) leveling the top standard layer, taking the leveled top standard layer as a time starting zero point of speed fitting, performing linear fitting on the acoustic logging speeds between all top and bottom layers in the work area, and calculating a fitting speed value w of each well at the position of the bottom standard layer according to a fitting curve;

(2) according to the fitting speed value, a time value t11 of each well at the position of the bottom standard layer is obtained by using a conventional time-depth conversion method, a difference value t33 exists between the time value and the seismic interpretation time t22 of the bottom standard layer, namely t22-t11= t33, a trend surface of all the difference values in the work area is obtained by using a least square method, and the value on the trend surface is recorded as t 44;

(3) using the value t44 of the trend surface to correct t11 in the step (2), wherein the time value of each well at the bottom standard layer position after correction is t55= t11+ t 44;

establishing a speed field based on the calibration result of the top and bottom standard layers;

and step six, generating a synthetic seismic record based on the velocity field in the step five and a conventional time-depth conversion method, and carrying out interlayer calibration of the well seismic by using the synthetic seismic record.

The fifth step in the scheme is specifically as follows:

a, calculating a difference value between a fitting speed value v corresponding to each well in a top standard layer and a speed of the standard layer, calculating a trend surface of the difference values corresponding to all wells in a work area by using a least square method, and recording a numerical value on the trend surface as vv;

b, correcting the fitting speed v corresponding to the top standard layer by using the numerical value vv on the trend surface to obtain the corrected top standard layer speed v1;

c, calculating the difference value between the fitting speed value w corresponding to each well in the bottom standard layer and the speed of the standard layer, calculating the trend surface of the difference values corresponding to all wells in the work area by using a least square method, and recording the numerical value on the trend surface as ww;

d, correcting the fitting speed w corresponding to the bottom standard layer by using the numerical value ww on the trend surface to obtain a corrected bottom standard layer speed w1;

and e, establishing a velocity field between the top standard layer and the bottom standard layer by using v1 and w1 and adopting a three-dimensional interpolation smoothing method.

The invention has the following beneficial effects:

1. the invention can synthesize the seismic recording speed by using the top and bottom reference layers as constraint and replacing acoustic wave conversion with acoustic wave speed between layers, eliminate space errors by means of mean speed fitting, trend surface low-frequency effect removal and the like, and obtain the well seismic calibration method of accurate speed between the top and bottom and standard layers.

2. The method can solve the problem of mismatching of well information and seismic data in time and waveform, reduces the influence of transverse heterogeneity on well calibration speed extrapolation, and has important application value on oil and gas resource exploration.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

The invention is further illustrated below:

the well-seismic calibration method comprises the following steps:

firstly, preparing seismic imaging data, well logging interpretation data, seismic interpretation standard horizon data and well logging interpretation standard horizon data according to the required work area range and the well logging quantity.

And secondly, selecting stratums with strong in-phase axis continuity and stable deposition characteristics from the explanation scheme as a top standard layer and a bottom standard layer respectively.

Thirdly, calibrating and controlling the top standard layer:

the method comprises the following specific steps:

a, performing linear fitting on all acoustic logging speed curves in a work area, and solving a fitting speed value v of each well at the top standard layer position according to the fitting curves;

b, according to the fitting speed value, a time value t1 of each well at the position of the top standard layer is calculated by using a conventional time-depth conversion method, a difference value t3 exists between the time value and the seismic interpretation time t2 of the top standard layer, namely t2-t1= t3, a trend surface of all the difference values in the work area is calculated by using a least square method, and the numerical value on the trend surface is recorded as t4;

c, correcting t1 in the step b by using the value t4 of the trend surface, wherein the time value of each well at the position of the top standard layer after correction is t5= t1+ t4;

d, knowing that the drilling platform and the seismic data datum plane have static correction difference t6, performing residual moveout correction on t5 in the step c to obtain a final calibration time value t7= t5+ t6 of the position of the top standard layer of each well.

Fourthly, calibrating and controlling the bottom standard layer:

the method comprises the following specific steps:

a, leveling a top standard layer, taking the leveled top standard layer as a time initial zero point of speed fitting, performing linear fitting on all interlayer acoustic logging speeds in a work area, and calculating a fitting speed value w of each well at the position of the bottom standard layer according to a fitting curve;

b, according to the fitting speed value, a time value t11 of each well at the position of the bottom standard layer is calculated by using a conventional time-depth conversion method, a difference value t33 exists between the time value and the seismic interpretation time t22 of the bottom standard layer, namely t22-t11= t33, a trend surface of all the difference values in the work area is calculated by using a least square method, and the numerical value on the trend surface is recorded as t 44;

c, using the value t44 of the trend surface to correct the t11 in the step b, wherein the time value of each well at the bottom standard layer position after correction is t55= t11+ t 44.

Fifthly, establishing a speed field based on the calibration result of the top and bottom standard layers:

the method comprises the following specific steps:

a, calculating a difference value between a fitting speed value v corresponding to each well in a top standard layer and a speed of the standard layer, calculating a trend surface of the difference values corresponding to all wells in a work area by using a least square method, and recording a numerical value on the trend surface as vv;

c, calculating the difference value between the fitting speed value w of each well corresponding to the bottom standard layer and the speed of the standard layer, and calculating the trend surface of the corresponding difference values of all wells in the work area by using a least square method, wherein the numerical value on the trend surface is marked as ww;

d, correcting the fitting speed w corresponding to the bottom standard layer by using the numerical value ww on the trend surface to obtain a corrected bottom standard layer speed w1;

and e, establishing a velocity field between the top standard layer and the bottom standard layer by using v1 and w1 and adopting a three-dimensional interpolation smoothing method.

And sixthly, generating a synthetic seismic record based on the velocity field in the step five and a conventional time-depth conversion method, and carrying out interlayer calibration of the well seismic by using the synthetic seismic record.