Research On Anti - Skew - Oblique Skew Technology Of Carbonate Strata In

Well deviation is one of the major technical problems in oil drilling engineering. Well deviation is not only make the vertical wells deviates from the geological target, increase the friction torque of inclined well,and increase the risk of downhole complex accident,but also affect the cementing quality, slicing, water injection response. So the study of straightening technology of inclined well of great significance to improve the oilfield exploration and development comprehensive benefits.This paper studies the formation and evolution characteristics of the regional structure, and the pattern of the structure and the features of fracture system. On the basis of analyzing drilling tool structure, diplog and well history data, and by analyzing the carbonate formation of tower anisotropy index, formation deviating index and orientation drift coefficient, we can draw a conclusion that:Triassic Carboniferous Or dovician have a strong ability to change the hole deviation, so we should pay attention to the change of hole deviation and orientation.The mechanism of anti inclined screw drilling tools has been analyzed, and by using the finite element analysis method, we have established mechanical model of control hole deviation of screw drill tool. By analyzing the single curved screw drill tool, we can draw a conclusion that:the farther stabilizer position from bit side the larger bit side force; drilling pressure does not have obvious influence on bit side force; bend angle and elbow point location have obvious influence on bit force; Single bend screw drill tool has strong straightening ability in big deviation angle. By field application we can find that screw drill tool is verified inclined effect in carbonate formation.Based on the finite element model of drill string, the pendulum assembly finite element mechanics analysis shows that:in small deviation angle, the bit side force of single stabilizer pendulum is more sensitive than double stabilizer pendulum; while in big deviation, the bit side force of double stabilizer pendulum is superior to the bit side force of single stabilizer pendulum.