Optimal Design Of Under Balanced Drilling In Xu Shen 1 Gas Field

Underbalanced drilling technology is effective to protect oil and gas reservoir, to overcome the drilling accident and lost circulation, reduce the water sensitivity of mud shale hydration and improve drilling speed, etc, are widely used in oil and gas exploration, development and drilling engineering, and achieved good application effect. Well bore structure design, selection of drilling fluid, the control of bottom hole pressure is, the key technology in underbalanced drilling, the adaptability of different reservoir. Xu has a good prospect of reserves, deep 1 gas field formation is given priority to with conglomerate, sandstone and mudstone, belong to the category of the application of underbalanced drilling. In drilling, because of the large deep rock hardness in volcanic rock, conglomerate formation bit wear serious, drilling rate is low; Fracture development part of blocks, there exists the poor cementation of broken stratum, prone to peeling, borehole wall collapse and malignant leakage complications, such as drilling process needs to be optimized.In this paper, aiming at the existing problem of xu has deep 1 gas field drilling, from the design of well bore structure, selection of drilling fluid, the control of bottom hole pressure is analyzed in three aspects: the research and optimization design, gives the depth by xu deep 1 gas field, the drilling fluid system and bottom hole pressure control method, as a case study of xu deep level 2 Wells in field application practice, good results have been achieved. Other Wells of xu deep 1 gas field application of this technology to provide guidance, as a whole long deep field development speed and efficiency, to achieve the best development effect.