The Petrophysical Evaluation Of Fractured Buried-hill Reservoir And Its Application In Suderte Oilfield

Fractured buried-hill reservoir in Hailar basin is characterized by complex lithologies and reservoir types, so the effective pay zone are hard to be identified with low interpretation resolution of reservoir parameters. In order to solve these problems, based on petrophysics, geology and reservoir engineering theory, a series studies are carried out on lithology identification, fracture description, interpretation method of reservoir parameters and effective thickness interpretation criteria of fractured buried-hill reservoir by using core, conventional logging, imaging well logging, mud logging, oil testing and production behavior data, forming a set of comprehensive well logging evaluation techniques for fractured buried-hill reservoir, which bring forth new ideas in logging response numerical simulation of dual laterolog of net-fractured reservoir, fracture porosity scale and reservoir parameters interpretation of dual porous media, and guide the discovery of the proved reserves of 3000×104t and the design of development plan. The following results are obtained:(1) Based on the lithology analysis of core data, complex lithologies in this area are identified by using vector computing technique, with high identification resolution for slag and tuffaceous mudstone, which can meet the needs of well log evaluation. The lithologies of the reservoir are mainly volcaniclastic rock and volcaniclastic sedarenite.(2) By analyzing the core data of the reservoir in Suderte oilfield in Hailar basin, it is determined that reservoir space of Budate Group consists mainly of high angle structural fracture and dissolved pore, and that Budate Group reservoir is dual porous media type with the support of oil testing and well testing.(3) Adopting the finite difference method based on resistance network, the theory study is conducted on dual lateral resistivity logging responses of single fracture, multi parallel fractures and network fractures, and the dual lateral resistivity logging response rule of the fractured reservoir in this area is found out.(4) By the guidance of the theory of dual lateral resistivity logging curve responses, combined with the fracture response characteristics on FMI and cross-coupling acoustic logging data, the conventional logging response pattern of different kinds of fractures is established. The fractured reservoir is identified by using three porosity logging ratio method, differential ratio method of resistivity and curve change ratio method, and the comprehensive probability method is formed, realizing the identification of fractured reservoir by using conventional log method.(5) Based on porosity spectrum analysis and laboratory analysis techniques, the porosity of fracture-cave and matrix in fractured reservoirs are determined, and the saturation of fractured reservoir is determined by using mercury penetration data and analogy analysis, which is helpful to parameters determination of dual porous media reservoir.(6) Based on the technologies of single-well fine processing and multi-well comprehensive analysis, combined with the oil test and production test, core description and comprehensive well logging data, the effective criteria and workflow for netpay division and reservoir classification for Budate Group of Suderte Area in Halaer Basin has been established, realizing comprehensive logging evaluating for fractured reservoir of Budate group of Suderte Area in Halaer Basin.