Real-Time Prediction and Optimization of Drilling Performance Based on a New Mechanical Specific Energy Model

The theory of mechanical specific energy has been of great value in real-time evaluating drilling performance. Given the mechanical specific energy (MSE) of bit could not be precisely calculated at present, this work presents a new mechanical specific energy model based on the evaluation of virtues and defects of available MSE models. Meanwhile, ROP can be predicted by further deducing the model. According to the relations between MSE, CCS, drilling parameters and ROP, a real-time drilling performance predicting and optimizing method is proposed by analyzing bottom-hole conditions of drilling and determining the reasonable drilling parameters. The new mechanical specific energy model and the real-time optimizing method are tested through field logging data. The results show that the calculation precision of the new mechanical specific energy model is the highest, and the calculation error is the minimum both in vertical section and horizontal section, which can make MSE applied more widely including horizontal wells and can be quantitatively applied. The prediction accuracy of ROP is very high, which can fully meet the needs of engineering of the field. The real-time drilling performance predicting and optimizing method with highly diagnostic accuracy, effective optimizing and simple operation are demonstrated by field examples, and it is worthy to be applied and promoted.