كاربرد ضرايب الاستيك(LMR) در تعيين خصوصيات مخزني در محيط آزمايشگاهي و انطباق با خطوط لرزه اي در يكي از ميادين نفتي جنوب غرب ايران

Application of LMR in Reservoir Characterization and Seismic Line Properties in One of the Carbonate Reservoirs in South West of Iran

A certain carbonate reservoir in southwest of Iran provides the opportunity to validate LMR (Lambda Mu Rho) as a characterization technique, while lithological is still the main characterization method. In an area where reservoir is poorly imaged by amplitude changes and where acoustic impedance alone fails to separate high porosity-permeability reserves from lower ones, LMR can be an important tool. The significance of this method has not been examined in carbonate reservoirs. Lambda is an elastic parameter relating to incompressibility and is sensitive to pore fluid type. Shear modulus (Mu) is an elastic parameter corresponding to rigidity which is sensitive to rock matrix type. These two variables, were calculated bases on rock physics measurements and 2-D seismic experiments. Rock physics lab studies were carried out on 40 samples which were collected from 4 wells of the reservoir. Initial LMR values around the reservoir were based on rock physics lab measurements. Porosity and permeability studies of these 40 samples, helps detection of high porous samples from lower ones. Then according to LMR values; samples were categorized into two groups: those exhibiting a good potential for being a reservoir and ones with lower reservoir properties. The next step was calculating LMR values from seismic data, therefore P-wave and S-wave reflectivity were extracted from prestack seismic P-wave gathers. Inversion of reflectivity estimates may lead to calculation of P- and S-impedance, density, and also lame parameters (k.p, M.p). The variation of Mu rho (Mp) across the field reveals that this is an efficient method for detection of high porosity-permeability zones from lower ones in the carbonate reservoirs, and a good agreement exists between results of rock physics lab and seismic data, however Lambda rho (Xp) is not a reliable technique for discrimination between oil and brine saturation.