A New Concept of RMF as Create the Relation Between Facies and Rock Mechanic: A Case Study From Asmari Reservoir

Abstract

Description of formation properties and rock mechanical parameters with higher accuracy results is in reasonable wellbore stability predictions for any locations in a field prior to drilling. The Asmari formation in the studied oilfield has mixed carbonate-siliciclastic lithology and its elastic modulus changes are correlatable with facies changes. To address these changes, we investigated the relation between sedimentary environment (facies) and texture with various elastic moduli. Among the elastic modulus Young's modulus (E) shows a higher correlation with porosity and facies. The present study evaluates the rock elastic properties based on E and facies textures in the Formation, and aiming to define the Rock Mechanical Facies (RMF). Thus, the main objective of the present study is to evaluate rock elastic changes (E) in the framework of depositional environments (facies) and their sedimentological characteristics. Sedimentary features and depositional textures are reflected in the effect of porosity on the elastic parameters, therefore these parameters are also affected by porosity. The result of this paper shows that E is strongly controlled and correlated to sedimentary properties of reservoir rocks that useful information from ductile-brittle zonation of the reservoir. These RMFs are found as an effective tool for correlation of E between wells and propagation of the results from wells to the field scale. In each RMF mean of parameters as Avg. E, Avg. Ø, ratio of particle or grain to cement or mud, dominant pore type and brief facies/texture descriptions respectively are descripted: RMF1: 10×106 psi; 7%; <1; Micropore; Mudstone/Dolomudstone & Wackestone, Intertidal, Restricted Lagoon & Deep Marine. RMF2: 8×106 psi; 15%; 1; Fine Interparticle & Intercrystalline, Moldic & Vug; Wackestone & Packstone, Back-Shoal or Lagoonal Shoal Margin, Tidal Channel, Open Lagoon and Shallow Open Marine. RMF3: 4×106 psi; 20%; >1; Coarse Interparticle & Intercrystalline; Ooids, Intraclasts & Bioclasts Grainstone, Shoal. RMF4: 11.5×106 psi; 3%; <1; Micropoe, Moldic & Vug; Packstone to Dolomitized Grainstone, Back Shoal & Shoal. RMF5: 4×106 psi; 22%; >1; Coarse Intergranular; Arenite, Barrier Island & Incised Valley Filled. RMF6: 5×106 psi; 12%; 1; Fine Intergranular; Quartz Wacke & Sandy Mudstone, Lower Shoreface to Offshore, Upper Shoreface & Intertidal. RMF7: 8.5×106 psi; 5%, <1;Micropoe; Quartz Wacke & Sandy Mudstone, Lower Shoreface to Offshore, Upper Shoreface & Intertidal.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016