The Refined Reservoir Description To The Shabei Oil Field J₂x₁

Shabei Oil Field is situated in the Shanan block-faulted area of the fold belt in the eastern bulge of Junggar Basin. Currently, the targeted horizon of reservoir is J2x1. Since this oil field belongs to the complex part oil field, with large numbers of large faults and minor faults developed and structure fracturing existing in the block-faulted area, the problem of misunderstanding of the local structure is serious. Before conducting this research project, only regional deposition backgrounds was once studied, and sedimentary micro-facies and reservoir characteristics still need in-depth study. Besides, the information collected about the first reserve is not accurate. All this problems severely restrict the development of fault block. Therefore, in order to have a further understanding about this fault block, the refined reservoir description research needs to be developed urgently.Taking the reservoir of J2x1+2in Shabei Oil Field as an example, this thesis conducts stratigraphic classification and compares different strata, introduces a new explanation about well-seismic-based structure elucidation, well log interpretation, and sedimentary microfacies analysis. The research results are mainly as follows:(1) Stratigraphic classification and strata correlation are conducted under the basic principles of sedimentary and begin with stratigraphic analysis of the key wells. The principle of this classification is that it is must conducted under the control of the key horizon with the method of cycle control and graded stratigraphi correlation. Under the control of the sedimentary cycle, refined classification and correlation about the backbone profile are conducted in the thesis. In the process of classification, the stability of the single sand layer must be considered and the classification must be detailed to the single sand body level. Taking the backbone profile well as standard, correlation between all the wells in the area are conducted, with a view to achieving the closing of the strata correlation in this area. Totally, there are56wells participating in the classification and correlation. The J2x1are divided into two mono-sand bodies and eight fine strata. In the process of stratigraphic correlation, well-seismic-based method is made to the full use. The lateral continuity and the longitudinal high resolution of seismic phase make the results of strata correlation more reliable.(2) According to the well-log data, a high precision synthetic seismogram and multi-well calibration are made in this thesis. Through eliminating the ill effects of inclined shaft and much error well in the complex structure zone, the seismic phrase of the bed of interest is correctly calibrated. Then through the interactive fine interpretation to the three-dimension seismic data, the space distribution of the fault at all levels is also studied here. Through analyzing the fracture system properties and the fracture combination relations, the overall structure characteristics of the block are studied. With the well-log data, multi-direction reservoir section map is made. Studying the combinational relationships between the faults and then further studying and summarizing the rule of fault development. As for the low-level sequence of the minor faults, by taking the method of association of the activity and inertia, this thesis explains the correctness of results of the faults explanation.(3) The landform of this area is mainly the lake facies deltaic deposit. Based on the regional sedimentary background of J2x, under the guidance of the model of the lake facies deltaic deposit, this thesis studied the key wells and analyzes the single well facies with a view to building a knowledge base of the sedimentary microfacies; this thesis studies the core phase and marks the electrofacies with a view to establishing a logging identification chart of microfacies and classifying the microfacies of the fine stratus of all the wells in this area. Based on analyzing the sedimentary microfacies of the profile, the microfacies scattergram of the fine stratus is made in this thesis, with a view to analyzing the evolution of the lake facies deltaic deposit and the rule of the phase spreading. According to the research results of the sedimentary microfacies, this thesis analyzes the favored phase spreading.(4) Based on the analysis of the four characters (lithology, resistivity, physical character, and oil-bearing), lithology identification template and the permeability and porosity explanation model are established in this thesis. According to the water saturation model based on the Richie formula, parameters of56wells within this area like porosity, water permeability, saturation, shale content are calculated in this thesis. Based on the core analysis data, production test data of test wells and log information, effective thickness standard is established in this thesis and the effective thickness of reservoir in this area is partitioned in this thesis.(5)By using the Discover—a software and adopting a well point volume method, the reservoirs of well-area203, well-area2041, well-area205and well-area19are calculated in this thesis.The research result of this thesis is applied into Shanan block-faulted area. Practice proves that the research method conveyed in this thesis is advanced. Moreover, this method deepens and optimizes the theory and method of geology about continental fault block reservoir development. The research result is reliable and economical and social benefits are obtained significantly. Therefore, it has strong value to be popularized. Besides, it also has some guiding meaning to the study of the development of other similar oilfields...