Study On Optimization Of Horizontal Well Geological Parameters Of Weak Earthquake Reflective Zone In Seam - Dong Reservoir Of Tahe Oilfield

Since" the Twelfth Five-Year Plan", the development object of Tahe Oilfield has changed from large fracture-cavity as represented by the" strong string beadlike reflection" to hard-to-recover reserves featured by" the small string beads" and" weak reflection". The characteristics of weak seismic reflection are weak energy, cluttered phase, different event and weak rate of amplitude change, which is mostly the abnormal refraction of small fracture and cave in fracture-cavity reservoir. The shift in the development object is responsible for the unsatisfactory development effect of the horizontal well in Tahe Oilfield, primarily manifested as the failure of construction, low well productivity and short water-free production period. The main research object of this article are the geology parameter optimization of horizontal well, subsection optimization and fracture parameter optimization, and the main works and the corresponding achievements are as follows:(1)There are four typical types of weak seismic reflection. The main reservoir space has been researched, and there are three reservoir types have been summed up, which include cave, fracture-hole and fracture, and the fracture type’s drilling footage is the longest. By the analysis of main reservoir types of each type of weak seismic reflection, I come to the conclusion that the clutter weak reflection has the best reservoir quality.(2)By analyzing the current status of exploitation and the problems of locating horizontal wells in the area of weak seismic reflection, the optimization objectives of the horizontal wells have been set, including the orientation, length, vertical position, reasonable fracturing stage number and the fracture parameters of the horizontal wells.(3)Based on the finite element model, we found that different orientations of horizontal wells will influence the sidewall stability by simulation and analysis. By considering the relationship between the orientation of horizontal wells and the morphology of artificial fracture, we got the favorable orientation of horizontal well by the statistical analysis of the current crustal stress of Tahe Oilfield.(4)Based on the prediction model of acid fracturing horizontal well and the analysis of the length of finishing drilling horizontal well, we make calculation of reasonable length of horizontal wells in fracture and fracture-hole reservoir with the target of production.(5)Based on the discussion the influence of reservoir characteristics and oil water distribution, we made the reasonable suggestion as to the vertical position of horizontal well.(6)Based on understanding of reservoir characteristics in the area of weak seismic reflection, for the subsection problems of acid fracturing horizontal wells in the area of weak seismic reflection, combining geology, seismic, drilling and logging data, five evaluating indicators of subsection evaluation have been selected and the corresponding evaluation criterion has been set. formed a subsection optimization method with pertinence and scientificalness, and optimized the subsection of five typical wells.(7)Based on the prediction model of acid fracturing horizontal well, the influence of fracture parameters such as length, interval and angle on the production of acid fracturing horizontal well in the area of weak seismic reflection has been calculated and analysed, and these fracture parameters have been optimized.