Research on evaluation method of rock drillability based on drilling cuttings measurement

ABSTRACT: The drillability test of downhole core, automatic mineral analysis of drilling cuttings and rock mechanical parameter evaluation of electrical completion data were carried out for deep difficult-to-drill formation. A petrophysical model of drilling cuttings considering formation composition and structural characteristics was established, and an evaluation method of rock acoustic parameters while drilling was formed. The evaluation model of formation drillability based on acoustic parameters is established based on the laboratory measurement of formation acoustic velocity and the drillability test during micro-drilling. Through the comprehensive test and verification of drilling cuttings, completion electrical logging and core drillability data, the evaluation technology of cuttings rock drillability while drilling is finalized. The evaluation technology of formation drillability based on drilling cuttings measurement has the advantages of low cost, timely evaluation and high reliability, which can provide technical support for drillability evaluation in deep formation area and selection of drilling bit for drilling speed increase.