地震褶积方法制作合成地震记录
包括,(1)读取相模型,设置每种相的密度和速度,(2)计算反射系数,添加噪音,(3)设置子波,(4)进行褶积计算。具体的代码如下
- void syntheticSeis(const string& faciesFileName, const string&synseisFileName,
- vector
int , double, double>>faciesDenVelocity, - double dt, double fm, int convLength)
- {
- const double PI = 4 * (4 * atan(1.0f / 5) - atan(1.0f / 239));
- IModel3D<int> facies;
- facies.loadNumpy(faciesFileName);
- int ni = facies.getNi();
- int nj = facies.getNj();
- int nk = facies.getNk();
- auto faciesList = facies.getValueVec();
-
- for (auto item : faciesList) {
- bool find = false;
- for (auto fv : faciesDenVelocity) {
- if (get<0>(fv) == item) {
- find = true;
- break;
- }
- }
- if (find == false) {
- std::cout << "fail to find facies " << item <<
- " in facies_velocity_set" << std::endl;
- return;
- }
- }
-
- // define the velocity of each facies
- auto impedance = IModel3D<float>(nj,ni,nk,"veclocity");
- const int* faciesPtr = facies.grid().data();
- float* impPtr = impedance.grid().data();
- random_device dev;
- default_random_engine rnd(dev());
- uniform_real_distribution<double> u(0.95, 1);
- for (int i = 0; i < ni * nj * nk; i++) {
- int faciesV = faciesPtr[i];
- for (const auto& item : faciesDenVelocity) {
- if (get<0>(item) == faciesV) {
- //impPtr[i] = get<1>(item)* get<2>(item);
- impPtr[i] = get<1>(item) * get<2>(item) * u(rnd); //with noise
- break;
- }
- }
- }
-
- // define the reflection coefficient
- auto refCoef = IModel3D<float>(nj, ni, nk, "reflectionCoefficient");
- for (int j = 0; j < nj; j++) {
- for (int i = 0; i < ni; i++) {
- refCoef.setValue(j, i, nk - 1, 0);
- for (int k = nk - 2; k >= 0; k--) {
- float imp1 = impedance.getValue(j, i, k + 1);
- float imp2 = impedance.getValue(j, i, k);
- float coef = (imp2 - imp1) / (imp2 + imp1);
- refCoef.setValue(j, i, k, coef);
- }
- }
- }
- float vMin = FLT_MAX, vMax = -FLT_MAX;
- refCoef.getMinMax(vMin, vMax);
- std::cout << "refcoef vmin= " << vMin << " vmax= " << vMax << std::endl;
-
- // calculate syntheic seismic
- int n = convLength;
- auto rickerWave = [=](int kk)->float {
- return (1 - 2 * pow(PI * fm * dt*kk, 2)) * exp(-pow(PI * fm * dt*kk, 2));
- };
-
- // define the synthetic seismic trace
- auto synSeis = IModel3D<float>(nj, ni, nk, "syntheticSeis");
- for (int j = 0; j < nj; j++) {
- for (int i = 0; i < ni; i++) {
- for (int k = nk - 1; k >= 0; k--) {
- // seismic convolution
- double trace = 0.0;
- for (int t = -int(n / 2); t<int(n / 2); t++) {
- if (t + k < 0 || t + k >= nk)
- continue;
- else
- {
- double riker = rickerWave(t);
- double coef = refCoef.getValue(j, i, k + t);
- double value = riker * coef;
- trace += value;
- }
- }
- synSeis.setValue(j, i, k, trace);
- }
- }
- }
- synSeis.saveNumpy(synseisFileName);
- vMin = FLT_MAX;
- vMax = -FLT_MAX;
- synSeis.getMinMax(vMin, vMax);
- std::cout <<"create syntheitc seismic"<
" synseis vmin= " << vMin << " vmax= " << vMax << std::endl; -
- }
读取的参数文件
参数文件
#option data for create synthetic seismic trace
ricker_fm 25
ricker_dt 0.002
ricker_conv_length 40
#define density velocity of each facies
max_facies_num 12
facies_den_velocity_0 0 0.1 3000
facies_den_velocity_1 1 0.1 3200
facies_den_velocity_2 2 0.1 3500
facies_den_velocity_3 3 0.1 3200
facies_den_velocity_4 4 0.1 3500
facies_den_velocity_5 5 0.1 3200
facies_den_velocity_6 6 0.1 3500
facies_den_velocity_7 7 0.1 3200
facies_den_velocity_8 8 0.1 3500
facies_den_velocity_9 9 0.1 3000
facies_den_velocity_10 95 0.1 3200
facies_den_velocity_11 100 0.1 3200
files_contians_npy3dfile_at_each_line npy3dfiles.txt