Rock Physics And Oil And Gas Reservoir Identification Of Carbonate Rocks

Along with the oil and gas exploration and the development of the deepening of the reservoirs, the identification of oil and gas reservoirs become more and more difficult, so we need more technology to strengthen the underground geological body and lithology identification, and then seismic rock physics, which keep describing quantitatively the close contaction between the rocks and the oil or gas, set up a bridge between seismic exploration and the rock physics.The rock samples was tested on the experiment which was simulated the conditions on the formation temperature and pressure. It made people understand the relationships between the structure of rocks and the seismic wave velocity of rock. The physical relationships between the seismic wave propagation characteristics and the reservoir parameters were known. It is judged to lithology, identificat the layers of oil and gas and determinate lithologic boundaries to provide a theoretical basis. Although the carbonate rocks have small in the possession of small sedimentary rocks, it has large reserves of oil and gas, and is important to increase the reserves of oil and gas exploration targets. Seismic rock physics Exploration of the carbonate is very necessary. In this article, carbonate was the main target for the following aspects research and was made important understanding.First, the author made the brief introduction of the basic principles of the MTS test system, introduced the measurement methods of lithology and acoustic parameters, and led in the standards and the methods of the carbonate rocks samples preparation.Second, to analyze several of elastic parameters data which tested in the laboratory summarized mainly the relationships between temperature and P-wave velocity or S-wave velocity of carbonate rocks, pressure and P-wave velocity or S-wave velocity, density and P-wave velocity or S-wave velocity and porosity and P-wave velocity or S-wave velocity , established the mathematical model between them, and then expanded the density - velocity relation ,and corrected the relation and fit, the relationships of gas saturated, oil saturated and water saturated carbonate shear between wave velocity and wave impedance were made and were applied on the actual area data to comparative and to get a better application results. And also the author introduced the attenuation coefficient and quality factor of the rock, analyzed and discussed the changement relations of the elastic wave attenuation and the confining pressure or temperature.Third, several kinds of effective medium models and the Biot-Gassmann theory were introduced and the process about the theory of Biot-Gassmann fluid substitution was summarized, and the fluid in the rocks was substituted for the others, which ranged from different fluid saturation. The results were analyzed on the replacement and the impacts were analyzed on pore elastic characteristics of rocks in a certain extent.Finally, the principles of quantitative cross plot technique were introduced and it was applied. A series of fluid factors were analyzed, the sensitivities of fluids identification were summarized. Basis on the previous principle of fluid identification factors, a new fluid identification factor was constructed. In order to prove its usefulness, the data which was experimented with three kinds of fluid-saturated sandstone by Hilterman was firstly analyzed. The results analyzed could prove that the new fluid identification factor was useful on fluid identification, and then it was applied to practical data. The new factor was applied in the LG region seismic data and well logging data to identify the fluids in rocks, its` applications had a better result and it was very useful and practical.