基于振动实测的非均质地层钻头失效分析与对策

四川盆地作为国内页岩气开发的重点区域,通过近几年的不断攻关和实践,机械钻速得到了提高,但由于受地层复杂、可钻性差、非均质性强等地质因素的影响,导致井下钻柱系统不良振动剧烈,容易出现钻头损坏严重、钻速较低等问题,严重影响了钻井时效。为了解决上述难题,以该盆地涪陵工区上二叠统龙潭组—中二叠统茅口组为例,采用井下振动高频测量工具的实测手段,测量了钻头—钻柱系统的动态振动加速度参数,结合地层的岩性和矿物组分分析,研究钻头失效原因与对策,并开展了现场试验。研究结果表明:①在非均质地层中钻进的钻头—钻柱系统产生了大于40 m/s~2的高幅值瞬时冲击振动,高幅值的瞬时冲击是导致钻头先期失效的主要原因;②提出了抑制高幅值的瞬时冲击振动采用"减振+增压"工具组合和避免井下工具共振的钻井参数;③采用钻井新参数的试验井比邻井的高幅值瞬时振动降低了17%,单只钻头进尺增加24%,钻头工作环境得到了较大的改善,钻头使用数量减少。结论认为,该研究成果能够有效地改善钻头—钻柱系统的振动状态,有利于达成延长钻头使用寿命的目标。     

井壁强化与堵漏双作用可钻水泥实验研究

针对常规复合堵漏材料之间无胶结、易被钻井液冲刷、使用油井水泥堵漏会造成新井眼的问题,研究开发了井壁强化与堵漏双作用可钻水泥。将超细碳酸钙粉体加入新型胶凝材料硫铝酸盐水泥中,调节胶凝材料的可钻性,研究表明,当超细碳酸钙粉体的加入量不大于7%时,水泥凝胶材料的强度随粉体加入量的增加而增加,而当粉体的加入量大于7%时,水泥凝胶材料的强度随粉体加入量的增加而减小,即可钻性变好;在硫铝酸盐中加入0.4%减水剂、0.3%提黏剂、0.6%缓凝剂时,其稠化时间达到155 min,为安全施工提供了条件;在可钻水泥中加入12%鳞片状云母、1%纤维、1.5%石灰岩颗粒作为堵漏剂,较好地增强了体系堵漏性能,能够较好地封堵3 mm和5 mm缝板裂缝。可钻水泥的研发为实现钻井过程中井壁强化与堵漏双作用提供了技术保障。      

铜坑矿92号矿体可钻性及可爆性研究

通过室内试验和现场测试，获取了大量相关的试验数据，对波阻抗、爆破性指数等9个参量进行了测定，分析探求了这9个参量之间的内在相关性。认为在通常情况下．可通过测试波阻抗值对矿岩的可钻性进行初步评价。根据波阻抗值将矿岩的软硬程度分为7级。得出了92号矿体易爆难凿的结论。     

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模拟井底应力条件测量岩石的可钻性是非常困难的，而常压下岩石可钻性与井底围压下岩石可钻性相差较大，远不能满足工程需要；章通过室内试验，建立了岩石可钻性级值与岩石力学参数的相关模型，再把井底围压下的岩石力学参数代入此模型中计算，可以得到井底应力条件下的岩石可钻性级值，通过在油气田的实际应用，取得了较好效果，能很好解决钻头选型和钻速预测这一问题。     

An estimation of the penetration rate of rotary drills using the Specific Rock Mass Drillability index

The main purpose of the present study was to provide a practical,convenient drillability prediction model based on rock mass characteristics,geological sampling from blast holes,and drill operational f...     

Rock drillability classification. Part II: Canonical representation of rock properties in the rock classification by fracture resistance

A multifactor classification of rocks by drillability is proposed based on canonical representation of the mechanical and structural properties of rocks by the dimensionless characteristics of rock fracture resistance. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6. pp. 86–104, November–December, 2008.     

应用NDR计算地层孔隙压力

该文介绍了一种现场预测地层孔隙压力的有效方法NDR标准化钻速法。该方法从钻压、转盘转速、及水力学方面对钻井机械钻速进行校正,使其影响因素仅与压差和地层有关,从而使NDR能够正确反映地层的可钻性。地层可钻性与地层的压实程度和孔隙破裂程度有关,因此NDR可以反映地层孔隙压力的情况。用NDR预测地层孔隙压力目前国内录井涉及很少,希望通过该文能为更好地预测地层孔隙压力、提高录井服务质量做出一些贡献。     

巴润铁矿岩石可钻性试验研究

岩石可钻性分级至今尚不统一,各种方法适用对象不同,目前流行的方法多针对石油行业的沉积岩,不适合金属矿山。对巴润铁矿分布复杂、变质化的火成岩进行了代表性广泛的取样,对其进行了全面的物理、力学特性实验;对牙轮钻穿凿各种岩体进行了现场试验。研究结果表明巴润铁矿矿岩的可钻性与物理、力学特性具有很好的相关性。     

Drillability prediction in some metamorphic rocks using composite penetration rate index(CPRI)——An approach

Assessment of drillability of rocks is vital in the selection, operation, and performance evaluation of cutting tools used in various excavation machinery deployed in mining and tunneling. The commonly used rock drillability prediction methods, namely, drilling rate index(DRI) and Cerchar hardness index(CHI)have limitations in predicting the penetration rate due to differential wear of the cutting tool in rocks with varied hardness and abrasivity. Since cutting tools get blunt differently in different rocks, the stress beneath the tip of the bit decreases until it reaches a threshold value beyond which the penetration rate becomes constant. In this research, a new composite penetration rate index(CPRI) is suggested based on the investigations on four metamorphic rocks viz. quartzite, gneiss, schist and phyllite with varied hardness-abrasivity values. The penetration-time behavior was classified into active, moderate, passive,and dormant phases based on the reduction in penetration rate at different stages of drilling. A comparison of predicted penetration rate values using DRI and CPRI with actual penetration rate values clearly establishes the supremacy of CPRI. Micro-structure and hardness-based index was also developed and correlated with CPRI. The new indices can help predict cutting tool penetration and its consumption more accurately.     

录井资料在钻头选型中的应用

通过开展利用录井资料进行钻头选型方面的研究,开辟一条钻头选型的新途径。文中通过现场实验和资料处理建立了录井参数与岩石可钻性关系模型,利用该模型结合新疆塔西南巴楚地区录井、地质、钻井资料进行钻头合理选型,得出该地区初步钻头选型结果,并在现场进行了初步应用,取得了较好的效果。