基于地震资料的钻速预测研究

钻井的机械钻速与钻头结构、钻井液性能、钻进参数和钻具组合等因素密切相关,但理论和实践表明,地层因素仍是影响钻速的最主要因素,它不仅直接影响钻速,而且也制约着钻井参数对钻速的影响.针对新探区的特点,可从地震资料中提取包含地震层速度、地质年代、地质构造、地层产状、地层岩性等信息,发掘这些信息与地层可钻性以及机械钻速间的内在联系.在充分利用地震资料的基础上,运用数理统计等办法,模拟和优选出了层速度与地层可钻性以及层速度与机械钻速间的定量计算模型,并最终形成一套基于地震层速度直接预测机械钻速的方法和技术.通过计算机编程对HN油田近20口井的机械钻速进行钻前预测,符合率均达70%以上,表明该方法能较科学地预测新探区的机械钻速,能为钻前钻井周期设计以及钻井招投标价格预算等提供有益的帮助.

Prediction to drilling rate based on seismic data

The mechanical drilling rate relates closely to drilling bit structure, drilling fluid property, drilling parameters and drilling tool constitution, but according to theory and practice formation factor is still the one that impacts the drilling rate most. The formation factor not only influences the drilling rate directly but also restricts the impact of drilling parameters on drilling rate. The inter-relations between formation drillability and the drilling rate could be found using the information extracted from seismic data such as seismic interval velocity, geochron, geologic structure, strata attitude and strata lithology, in terms of the characteristics of the newly discovered reservoir. Quantitative calculation models of interval velocity and formation drillability as well as interval velocity and mechanical drilling rate have been established and optimized based on seismic data, adopting mathematical statistics methods, as a consequence, method to predict the drilling rate based on seismic data has been formed. The drilling rate of nearly 20 wells in HN Oilfield have been predicted through computer programming before drilling, and the coincidence rate is above 70% , the results indicate that this method will scientifically predict the drilling rate and help to design drilling cycle and make budget for public bidding.