PDC取心钻头在新疆油田深部硬地层中的应用

APPLICATION OF PDC CORING BITS IN DEEP AND HARD FORMATION IN XINJIANG OIL-FIELD

在新疆油田深部地层中发育有泥页岩、灰岩、白云岩、硅质灰岩、花岗岩,其硬度高,研磨性强,可钻性级别高,传统聚晶金刚石取心钻头机械钻速非常低,使用寿命短,增加了起下钻次数,经济效益差。所以,设计一种能提高机械钻速的取心钻头就显得很有必要。本文对新疆油田深部地层中常见的5种岩石的可钻性、压入硬度、塑性系数和研磨性进行了测试。根据测试结果,结合PDC取心钻头设计理论和方法,设计出适用于新疆油田深部硬地层的新型PDC取心钻头。该取心钻头在现场应用中取得了良好的效果,机械钻速得到显著提高,岩心收获率在95%以上,对提高深井取心时效、降低取心作业成本都具有重要的现实意义。

There are shales, limestones, dolomites, siliceous limestones, and granites in the deep formation inXinjiang oilfield, they have high hardness, high abrasiveness, and high drillability. Traditional polycrystalline di-amond core drills have a very low ROP and a short service life, which increases the number of trips and has apoor economic performance. Therefore, it is necessary to design a coring bit that can increase the ROP. This pa-per tests the drillability, indentation hardness, plasticity coefficient, and abrasiveness of five kinds of rocks.Based on the test results, combined with the PDC coring bit design theory and method, a new type of PDC coringbit suitable for deep hard strata in the Xinjiang oilfield was designed. The coring bits have achieved results infield applications, the ROP has been significantly improved, and the core recovery rate is above 95%, which hasimportant practical significance for improving the efficiency of deep well coring and reducing the cost of coringoperations.