The volume of the facies discrimination indicates excellent separation of the lithological facies, consistent with well logs and petrophysical interpretations. Available corridor stack were used to understand the phase character of the seismic. Churning seismic attributes with principal component analysis. The equivalent polygon highlights on the crossplot where we would expect the gas sands in the two. Given what the stress does to the overburden, s v, one can use lambda rho and mu rho attributes to compute s h and s h. Typically this is done through interactive crossplot analysis of the lmr volumes which are often difficult to reproduce and save for future work. Since seismic attributes are correlated through the. Asides the notable separation observed in discriminating the hydrocarbon bearing sand from neighboring brine sand and shale, these properties highlighted trends and. After data importation, a log editing and conditioning were carried out. Lambda rho versus murho crossplot at well location.
Seismic inversion is essentially a very simple procedure. Interesting directions being pursued in seismic curvature. Low rop was exhibited by 43 wells with high porosity, low lambda rho, low murho, high curvedness and low pimpedance. P and simpedance inversion, lambda murho, elastic impedance and poisson impedance. Geomechanics of the microseismic response in devonian. Figure 5 zoning shows that the anomalous data points correspond to the w5000 hydrocarbon zone. May 01, 2020 attributes contributed by the client to the analysis were. The anelastic attenuation factor or q is a seismic attribute that can be determined from seismic reflection data for both reservoir characterisation and advanced seismic processing. The generation of lambda murho attributes was done using a multiattribute neural network algorithm. Gas log mu kappa gas mu lambda gas saturated moduli vs porosity. Seismic attributes are an invaluable aid in the interpretation of seismic data. Rock physics models and seismic inversion in reservoir. The first and second lame constants see section 3 multiplied with density are defined as lambda rho and murho. The murho versus lambda rho mrlr crossplot forms the foundation upon which these other properties are imposed because they are invariant and form the basic elements of the other moduli.
Attributes contributed by the client to the analysis were. Study of rock physics and seismic attributes of hydrocarbon reservoirs in sabah basin. The purposes of this analysis are to identify rock lithology and fluid contents of a reservoir and map the gas reservoir. Interesting directions in seismic curvature attribute applications seismic data chopra and marfurt, 2010 so that the interpreters have a better understanding of the geology, the play concept and are able to make more meaningful conclusions when it comes to prospect generation. To test the effectiveness of sqp and sqs attributes in discriminating the lithology and fluid effect, the crossplot of sqpsqs has been compared with other elastic properties. Murho crossplot in figure 4, the lambda rho values for gas sand in both wells are the lowest while the shale has the highest lambda rho values. The values seismic inversion attributes added to the study includes improved and robust fluid and lithology discrimination. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. Various crossplots of results are used to distinguish differences between rock types, as shown below. Lambda rho and murho logs are identified to be sensitive to the. Figure 4 attribute cross section showing hydrocarbon intervals from the lambdarho versus murho crossplot. Pranter1 4 conocophillips school of geology and geophysics, university of oklahoma, usa 5 100 e. This algorithm works by identifying all possible linear and non linear relationships that may exist between the desired log attribute and the several available seismic attributes at the well location. B displays the lambda rho and murho crossplot, applied using well2.
Near and far stacks, intercept vs gradient analysis and the fluid factor. Correlation of avo inversion methods with porosity seen on logs and cores. When properly transformed, analyzed and interpreted, seismic attributes can be used to qualitatively and. Cross plot analysis of extracted seismic inversion. Final density, lambda rho, murho, poissons brittleness, poissons ratio, shear impedance, brittleness coefficient, and pimpedance. Gassmann fluid substitution, lower hashinshtrikman bound porosity. The crossplot analysis was carried out to determine fluid and lithology response of the rocks. A case study for mississippian chert reservoir of oklahoma, usa. Lambda rho and mu rho logs are identified to be sensitive to the. Since their introduction in the early 1970s, complex seismic trace attributes have gained considerable popularity, first as a convenient display form, and later, as they were incorporated with other seismicallyderived measurements, they became a valid analytical tool for lithology prediction and reservoir characterization.
Introduction to the special section on seismic attributes. Various crossplots of results are used to distinguish differences between rock types, as. The aim of the study was to integrate rock physics models and seismic inversion to improve the characterization of a selected reservoir using welllog and 3d seismic data sets. Application of extended elastic impedance eei inversion to. In a seismic inversion the original reflectivity data, as typically recorded routinely, is converted from an interface property i. Pioneering work on computation of stress estimates from seismic data has been done by goodway et al. The objective of this talk is to make sense of all of these.
The combination of attenuation attributes separate shale and gas sand at the well3 target. Prestack seismic data analysis with 3d visualization a. Attribute analysis in unconventional resource plays using. Enhanced prospect definition using well and 4d seismic. The result of the eei lambda rho versus eei murho crossplot was applied to the seismic data to create the volume of the lithological facies discrimination.
Segments of lambda rho and mu rho sections and their crossplot lambda rho section murho section fig. Correlation of avo inversion methods with porosity seen on. The lambda rho lrmurho mr or lmr crossplot space has been adapted by goodway et al. Classification of seismic attributes the seismic attributes are. Classification of seismic attributes the seismic attributes are classified basically into 2 categories. Example 1 the first example is a barnett shale gas play. Crains petrophysical handbook seismic attributes basics. The p and simpedance results from neural network analysis were used in the calculation of lambda rho and murho attributes. A seismic gamma ray prediction color and wiggle trace using multiple seismic attributes and calibration to the gamma ray log inset. Fluid and lithology discrimination using rock physics. Pdf study of rock physics and seismic attributes of. Elasticbased brittleness estimation from seismic inversion.
Avo intercept, avo gradient, intercept multiplied by gradient, far minus near, fluid factor, etc. The vpvs ratio and lambda rho attributes gave the best indication of lithology types, while the lambda rho attribute demonstrated to be an excellent fluid discriminant. Hence, we derived few more attributes like vpvs, lambda rho, mhurho etc. The new lambda rho and murho seismic volumes i show better resolution, ii ties better to. The purposes of this analysis are to identify rock lithology and fluid contents of a reservoir and map the\ud gas reservoir. Seven reservoir sands were delineated using suite of. Visualization, analysis, and interpretation of seismic attributes for characterizing a carbonate reservoir joanne wang, duane dopkin paradigm, joanne. The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. This volume is then used for reservoir zonation identification, lithology estimation, and welltowell correlations. The crossplot for these two attributes is also shown. Seismic attributes and pattern recognition improved welllog classification using semisupervised label propagation and selftraining, with comparisons to popular supervised algorithms michael w. Seismic attributes and their applications in seismic. Sand body delineation and reservoir characterization using.
This is because the gas sand is more compressible than shale. Rock physics modelling and seismic inversion were carried out in an onshore niger delta field for the purpose of characterizing a hydrocarbon reservoir. Theory goodway demonstrated how lmr analysis can be used to identify gas sands. Seismic attributes were introduced as a part of the seismic interpretation in early 1970s any information of interest that can be derived from seismic is seismic attributes 3. It has been done analysis of lambda murho lmr attributes of 3d seismic data at x area below x\ud horizon. Application of extended elastic impedance eei inversion. Computation of curvature attributes on impedance data. It has been done analysis of lambda murho lmr attributes of 3d seismic data at x area below x horizon. Using log data and knowledge of a play or basin, the expected lmr response can be calibrated. Lambdarho processing tool to reveal full hydrocarbon. Introduction the original seismic data had been processed in 1995 and was onshore nigeria. Given what the stress does to the overburden, s v, one can use lambda rho and murho attributes to compute s h and s h. In reflection seismology, a seismic attribute is a quantity extracted or derived from seismic data that can be analysed in order to enhance information that might be more subtle in a traditional seismic image, leading to a better geological or geophysical interpretation of the data. The analysis shows that lambda rho attribute is more robust in fluid and lithology discrimination than murho attribute irrespective of the petrophysical parameters of the field considered.
The rate of penetration rop measures drilling speed, which is indicative of the overall time and in general, the cost of the drilling operation pro. Visualization, analysis, and interpretation of seismic attributes for characterizing a carbonate reservoir joanne wang, duane dopkin. The pseudo 3d can be displayed with poststack or prestack attributes. Avo attributes had been generated from the near and far stacks. The equations that underlie the socalled lmr method, popularized by bill goodway, convert pimpedance and simpedance into and equations. Geomechanics of the microseismic response in devonian organic. Visualization, analysis, and interpretation of seismic. This mississippianage organicrich shale is the reservoir for the barnett shale unconventional gas accumulation in the fort worth basin and is one of the most active areas in texas. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in. Using lmr for dual attribute lithology identification. Spectral decomposition volumes, curvature and similarity volumes, instantaneous attributes and. P and simpedance inversion, lambda mu rho, elastic impedance and poisson impedance. Figure 3 lambda rho versus murho crossplot from the seismic volume.
Cross plot analysis of extracted seismic inversion attributes. Jul 06, 2014 seismic attributes were introduced as a part of the seismic interpretation in early 1970s any information of interest that can be derived from seismic is seismic attributes 3. Cross plotting of rock properties for fluid and lithology. Correlation of seismic attributes and geomechanical.
In this study, five seismic prestack simultaneous inversion derived attributes, pimpedance, simpedance, lambda rho, murho, and youngs moduluspoissons ratio, are used as. Lambda rho vs vpvs property attributes of sp, density, porosity and resistivity were plotted on the zaxis for each cross plots. After depth conversion, such seismicderived volumes can be used for improved geosteering. Overview of seismic attribute analysis in shale plays. Multiattribute seismic analysis on avo derived parameters.
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