应用钻头与地层相互作用模型优化防斜钻具组合设计

应用钻头与地层相互作用模型，综合考虑钻头和地层各向异性、钻头侧向力及钻头转角对井斜的影响，提出了“井斜趋势角”概念。针对各向同性地层，推导了简单实用的“井斜趋势角”计算公式。分析表明，进行防斜钻具设计、优选钻井参数时，综合考虑上述诸因素对井斜的影响是十分必要的；与“钻头侧向力最大”或“钻头转角最小”等单一指标相比，“井斜趋势角”指标考虑因素更全面、设计（或评价）结果更可靠。

Optimized Desige of the Anti - Deflect Bottom- Hole Assembly by Using Rock - Bit Interaction Model

Based on the rock-bit interaction model, and taking into account the influence of anisotropic characteristics of rock and bit, as well as the bit lateral force and bit tilt angle on deviation, a new term named the trend angle of deviation (TAD) was brought forward. In addition, simple and practical formulae aiming to isotropic formation were derived. Conclusions were drawn as follows: (1) When designing the bottom hole assembly (BHA) to deviation control and optimizing drilling parameters (weight-on-bit, rotary speed etc), it was essential to consider the impacts due to all the factors above. (2) Comparing to the single criterions, such as the bit lateral force and bit tilt angle, the TAD criterion was more synthetical, more reliable.