Numerical Estimation And The Three-dimensional Reconstruction Of Bioturbated Reservoirs Of Ordovician,Tahe Oilfield

Bioturbation reservoirs are well-developed in the Ordovician of Tahe oilfield.Based on core and field outcrop observation,employing typical rock sample section,polarizing microscope,cathode luminescence microscopy,Three-dimensional X-ray microscope and X-ray diffractometer to investigate and analyze bioturbated area of Ordovician in Tahe oilfield and Tabei Bachu field outcrop.The results showe that:(1)Four kinds of bioturbation(Thalassinoides,Helminthopsis,Planolites and Skolithos)identified in study area,of which,the mineral component of burrow infillings is composed mainly of dolomite,accounting for more than 90%.The hosted sediments are micrite and their mineral composition is calcite.(2)With the help of Bioturbated Digital Analysis Images Package of Adobe? Photoshop? software CS6,the study is carried on the core to identify and estimate quantitatively the area that was bioturbated in the core digital image.The “Similar Pixel Selection Method” is suit for the samples with high bioturbation,small size and high diversity,and “Magic Wand Method” has an advantage on the samples with large size trace fossils and good continuity as well as different color of infilled material.(3)Applying three-dimensional X-ray microscope,geological model of bioturbation carbonate reservoir in the study area is estabilished,and multiple extracting the morphological characteristics of the bioturbation and pore characteristics.Using the three-dimensional reconstruction software package by 3ds Max software,three-dimensional reconstruction of developmental characteristics and evolution law of the burrow is conducted,and Three-dimensional geological model of bioturbation reservoir in the study area is established.This study visualizes the internal structure and microscopic features of the bioturbation reservoir in Tahe oilfield and lays a solid academic foundation for subsequently investigating macro-heterogeneity and micro-anisotropy,calculating the tortuosity of porous media and quantitatively characterizing the percolation characteristics on the microscopic scale of those bioturbation reservoirs.It provides a new idea to improve and perfect the new model of Ordovician reservoir of Tahe oilfield.In addition,it also enriches geologic theory of carbonate reservoir,guiding the hydrocarbon exploration of the bioturbated reservoir,calculating reserves and selecting the best plan of the development of oil and gas fields.