【作者】 刘文；

【导师】 阎铁；

【作者基本信息】 大庆石油学院 ， 油气井工程， 2002， 硕士

【摘要】 欠平衡钻井技术是继水平井技术之后在钻井技术上的另一大发展方向和热点，尽快掌握和发展欠平衡技术是更好地发现油气藏和保护油气藏的战略措施。 在石油勘探及钻井过程中，对地层压力预测显得十分重要，搞好压力预测工作，可为钻井参数设计和井身结构设计提供重要的压力技术数据，对保护油气层，提高钻井成功率，降低钻井成本具有重要意义。 在钻井过程中只有准确掌握地层压力才能有效的确定井身结构、钻井液密度及所采用的井口装置和钻井施工措施，为此国内外相继发展了许多地层压力预测技术。单独依靠任何一种方法都难以实现准确预测，现有计算地层孔隙压力模型方法可能在不同的地区不同的地质和沉积环境而有很大的变化，没有那种孔隙压力模式能够在任意地区一成不变的加以利用，应该综合各种方法的结果并加以比较，才能提高预测的准确程度。本文按钻进情况采用综合方法来进行地层压力预测，即钻前预测结合随钻预测从而使地层压力逐步精确化，在钻前阶段采用地震资料法，在随钻阶段采用标准化钻速法和岩石强度法。 利用地震的纵波数据，根据所建立的地震波速与地层孔隙压力关系模型使用直接预测法来进行地层压力计算，然后利用标准化钻速法和岩石强度法，通过钻井过程实时测量得到的钻井地质数据来预测地层孔隙压力。 利用地震资料钻前预测结合随钻钻井地质参数进行实时预测，通过现场实验证明，有效的克服了现有各种计算模型对不同区域、不同条件的依赖性，能提前准确的预测钻头下部未钻开地层的孔隙压力。 本文同时对影响欠平衡值大小的各个影响因素进行了深入研究，给出了负压差的设计原则。通过对井壁岩石坚固程度的研究，探讨了对垂直井和水平井进行负压值设计的不同特点，给出了欠平衡钻井的最大生产压差。更多还原

【Abstract】 Underbalanced drilling technique is a hot point and development direction of drilling techniques after horizontal well drilling. It is a strategy measure to developing the underbalanced drilling technique for discovering and protecting reservoir.It is very important to predict formation pressure during oil exploring and drilling process. It can supply important pressure technique data for drilling parameter design and well structure, and have important meaning for formation protection, enhancing drilling success rate and decreasing drilling cost.Many formation pressure prediction methods were developed throughout the world, for it is takes effect on deciding the well structure, drilling fluid density, well head equipments and drilling operation measures. It is very difficult to predict exactly by using only any one method, the results change a lot in different area and different geologic depositional environment, so the compositive methods should be taken for increasing the predicting accuracy. In the paper a compositive method is applied according the drilling conditions, the prediction before drilling and while drilling integrate together to make the result more accuracy. Seismic data method is applied before drilling; the standard drilling velocity method and rock strength method are applied while drilling.Based on the seismic compressional wave data, the directly prediction method is used to computer formation pressure according the relative model of seismic wave velocity with formation pressure; after that, using the standard drilling velocity method and rock strength method, the formation pressure can be predicted through the realtime geologic data while drilling.The method is proved on site that it overcomes the dependence of computer methods already existing to different area and different conditions; it can predict the formation pressure under the bit accurately.The influence factors on underbalanced value also be studied deeply at the same time and the design principle of negative pressure difference is given. Through the research on the wellbore rock firm degree, the different characters of negative pressure difference design for vertical and horizontal wells are discussed; and the max production pressure difference of underbalanced drilling is given.更多还原