Prophecy of Cutting Transport Ratio through a Relationship between Equivalent Circulating Density and Drilled Solid Concentration

Abstract

This manuscript aimed to propose a new approach in estimating the cutting transport ratio through a relationship between equivalent circulating density (ECD) and drilled solid concentration from different formations in a nearly vertical well. A laboratory test utilising drilled cuttings from North Kuwait Field was conducted to simulate drilled solids-laden mud for accomplishing this purpose. The drilled solids were taken from four formations, namely Radhuma, Tayarat, Hartha and Sadi. The rheological behaviour of the drilled solids-laden mud was conducted according to API Recommended Practice 13B. In addition to laboratory tests, a database was established from drilled solids produced in the three wells of the North Kuwait field. As a result of the laboratory tests and actual field data, new empirical equation between drilled solid concentration and equivalent circulating density was proposed. ECD from laboratory works matched with the ECD field at an R2 value of 0.93, proving the data’s reliability. This empirical equation can be used to calculate the cutting transport ratio and later can be used to optimise drilling operations.