Method And Experimental Study On Using Rock Cuttings To Detect Structural Rock Mechanics Parameters

In the process of oil gas drilling and development engineering, the mechanical property of the rocks is the necessary technical parameters. The selection of suitable drilling bits and optimized drilling parameters is of great importance. Especially on drilling site, the most important work is to master the mechanical properties of the drilling strata timely and accurately.Rock cuttings are another form of stratigraphic rock that human beings could obtain directly. Rock cuttings have the same mechanics parameters with the related stratigraphic rock. The test of the rock cuttings can reflect the mechanical parameters of the stratigraphic rock, which is quite reasonable and scientific.According to the current research situation, this paper analyzes the limitations of cuttings method and proposes group cuttings experimental method and single cuttings experimental method. Group cuttings is the test objects of group cuttings experimental method. The experiment has established the relationship between group cuttings intensity and rock mechanics parameters through the strength of group cuttings. The experiment of single cuttings takes an approach of getting into cuttings without breaking them. That is to say, using pressure heads with certain shapes invades cuttings and acquires the invasion parameter (Intrusive load and invasion depth) before the rock is broken, and constructs the relationship models with rock mechanics parameter.Based on the above two approaches and large numbers of experiments, the author has constructed the relationship models between rock cuttings mechanical properties and rock mechanics parameter. Meanwhile, the author has compared these two methods, found their suitable conditions and obtained appropriate approaches for different particle size of cuttings, which improves the accuracy of test data.The adopted cuttings method and established mathematical model of this paper not only can provide data and reference for acquiring rock mechanics parameter timely and accurately, but also can provide guidance of the selection of drilling bits and optimized drilling parameters. Acquired data can provide parameters and basis for borehole stability analysis, follow-up cementing operation and oil reservoir exploitation.