Influencing Factors and Countermeasures of Cementing Quality in Tangdong Area of Dagang Oilfield

Tangdong region of Dagang oilfield as a key block for high-efficiency storage enhancement, oil and gas are abnormally active, medium pressure stability during the cementation process is paradoxically outstanding against water leakage, and the quality of cementation is difficult to guarantee. For this purpose, the paper has carried out an analysis of the influencing factors of regional cementation quality, to find out the three main controlling factors that constrain the quality of cementation in this block, namely the quality of the wellbore, the formation characteristics and the cement paste performance, to propose effective technical measures for the main control factors, including the optimization of drilling engineering design in the previous period, the simulation before cementation and the on-site construction management measures. On site application of the three wells resulted in a significant improvement in the quality of solidification of the production casing and achieved an average of 88.36% of good quality cemented segment rate, of which the three segment trajectory was preferred for the TD3 well with a maximum deviation angle of 37.69°, which greatly reduced the difficulty of trajectory control, while the potassium salt polymer system and one drilling technique measure were preferred, providing good quality borehole conditions for the cemented construction and, based on the actual borehole situation, optimizing the centering guide, cement slurry column structure and the cemented construction plan. The cementation quality segment rate reached 94.05% and the block record was refreshed. The smooth implementation of the three wells not only provides a reliable basis for the subsequent wells in the Tangdong region, but also provides references and borrowing for improving the cementation quality in similar oil fields.