The Characterization Of The Seepage Channel In Jiuba District Of Heavy Oil In Junggar Basin

Junggar Basin is an important oil and gas area in China.With the development and utilization of energy,its abundant heavy oil resources attract more and more attention.The development of heavy oil reservoirs is mainly based on thermal oil recovery methods.During the long-term throughput development process,steam is continuously injected into the formation to form turbulence channels,and in some places surface leakage occurs.In this paper,the Junggar Basin heavy oil company,Jiushi District,as the research object,intends to identify the causes of surface leakage in the study area through the development of dynamic monitoring of electrical methods combined with geological data such as strata,structures,reservoirs,and production dynamic data.Possible surface leakage pathways provide reference for later production regulation and management of blowouts.A comparative analysis of well logging sections in wells in the study area shows that the gamma log curves of the contact between the top of the Qigu group and the Tugulu group are changed,and changes from positive cycles to negative ones.It can be seen that Qigu Formation and Tugulu Group There are unconformity contacts between them,unconformity surfaces provide lateral passages for leaks,and interpretation of the seismic data volume in the study area shows that some small faults have developed in the study area.These faults may extend to the ground to form cracks and become steam explosions.The advantageous passages;Comparing the calculation results of formation rupture pressure in the study area with the actual production injection pressure,we can see that the injection pressure of each well in the actual production process is greater than the fracture pressure of the formation,resulting in the formation of the formation under the action of the fracturing.The cracks provide a channel for the leakage of oil and water.Inversion analysis of reservoir sand bodies in the study area shows that the reservoir sand body is well developed and has good connectivity,and it is easy to form lateral hypertonic channels.The potentiometric monitoring of the study area shows that the resistivity difference in the area is large,and the resistivity increases significantly in the vicinity of the leak.The inversion of the potentiometric monitoring results yields three-dimensional spatial resistivity distribution characteristics.Cross-sectioning of the three-dimensional resistivity distribution shows that the resistivity changes significantly in the transverse direction,and it is inferred that there are small faults in the shallow portion.Longitudinal sectioning of the three-dimensional space combined with seismic data further confirms the existence of shallow faults and the distribution of fracture space.The planar inversion of the potential method inversion data is used to obtain the plane leakage channel distribution.Through the channel distribution,it can be seen that the channels are numerous and complex.Through potentiometric monitoring of the study area combined with geological analysis and surface outcrop investigations,production dynamics investigations,and ground leakage plugging analysis,it was concluded that there are mainly three types of surface steam pattern in the study area.Mode 1: There is a direct channel between the production well and the plutonium.The steam moves along the production layer and migrates to the place where the cover layer is weak.It moves upwards into the micro-fissures that are vertically penetrating,and is pulled out of the surface where the cover layer is weak.Mode 2: The steam channel forms a channel along the high-permeability sand body.At the same time,there may be serious formation loss in the channel.The steam leaks from the production well in multiple directions to the upturned channel,and then enters along the vertical micro-cracks.Shallow surface,from the weak cover to the surface;Model 3: There is a difference in lithology in the subsurface target layer,different lithology permeability varies,so the low permeability rock will change the direction of steam expansion in the high-permeability reservoir and The steam break channel is preferentially formed at the fracture.