Reservoir Prediction And The Seismic Facies Analysis Of Reservoirs With Organic Reef And Bank In Zhujiangkou Basin

Reef and bank reservoirs were perfect reservoirs for oil and gas in carbonate rock. They have a special structure of shape and better pore than surrounding rock. They h- ave widely hydrocarbon potentiality. However, because of carbonate rock were inho- megeneous, it is very difficult to identify and forecast reef and bank reservoir and to interpret the seismic data.In recent year, with the object complex degree of oil-gas exploratory developme- nt increasing and seismic interpretation technology being more and more mature day by day, seismic oil-gas forecasting technology develops toward fine.Reefs are general- ly grown in a special environment, so the distribution of reef and bank reservoirs con- trolled by sedimentary facies. Therefore we must find the favorable sedimentary facies and the distribution of it with seismic facies analysis before forecasting and assessing the reef and bank reservoirs. First of all, the paper analyse systematically the strata cha- racteristic of carbonate reservoirs, seismic response characteristic of the reservior of reef and bank facies. Second, we formulate the fundamental principle of the facies pla- ne method, and SOM waveform classification. At the same time, we formulate the algorithm of waveform classification, the method of transforming seismic facies to sedimentary facies. Moreover, we predict the parameter of the reservoir with the seis- mic facies analysis result. Finally, we applied multiple methods of seismic facies analy- sis in reef and bank reservior of in TK and HK area, and divided the sedimentary facies and discriminated the reef and bank facies, then we predict porosity with seismic logging, inversion result and seismic facies analysis result. Main results of that topic involve below:1,By analyzing the pattern of carbonate rock deposition, summarizes the envir- onment and deposition rule of the reef and bank reservoirs. Base of those geological laws, we summarize the laws of seismic response of it. There are many reefs in HK and TK area. We find lots of features about reefs reflection in horizon tracking. It directly provides an understanding of reef deposition for researchers.2,In the researching of Zhujiang Formation in Zhujiangkou Basin, we analyze the seismic facies and sedimentary facies with the method of seismic reflection analysis, neural network waveform analysis and seismic attribution in HK and TK area. With comparison of log data and the laws of transforming seismic facies to sedi- mentary facies, we divide carbonate formation into continental shelf facies and platf- orm edge facies in HK area and continental shelf facies, slope facies, platform edge facies, open platform facies. It make geophysical closely with geological to help to forecasting and assessing the reef and bank reservoirs.3,We propose a method to predict porosity base on sedimentary facies constrain. Base on seismic facies analysis, combining with the log and rock core data; then disti- nguish the different sedimentary facies and translate seismic information into geolog- y information. Secondly, the density and acoustic velocity data of log in single sedim- enttary facies used for the best statistic correlation expression between impedance and porosity. In this way, there are some expressions in different sedimentary facies. Lastl- y, those expressions are used to calculate the porosity. With geology interprettation in horizon, this method combines with geology disciplinarian effect- ively.Through this method, it is better to improve the porosity prediction precision and pore fluid predict- tion and reservoir evaluation.