Use of Drill Cuttings for Improved Design of Hydraulic Fracturing Jobs in Horizontal Wells

Abstract

Abstract Drill cuttings are powerful sources of information that have been used for several decades by well site petroleum geologists for qualitative evaluation of reservoir rocks. Additional cuttings work is carried subsequently in the laboratory. This includes, for example, the preparation of thin sections for petrographic work, and the evaluation of intergranular and microfracture porosity. Drill cuttings, however, have not been used to full advantage in horizontal wells drilled through tight formation. This study proposes a method for quantitative determination of porosity, permeability and rock mechanics properties from drill cuttings collected in horizontal wells. These properties are determined through a combination of laboratory, analytical and 3D simulation work. The laboratory work includes the determination of porosity and permeability in cutting samples with sizes equal to 1 mm or larger. The results are used for determining key geomechanical properties such as Poisson's ratio and Young's modulus; and the estimation of a brittleness index. The data extracted from the previous two stages are useful in 3D hydraulic fracturing simulation for designing multi-stage hydraulic fracturing in horizontal wells. Data extracted from drill cuttings are important as the amount of information collected in horizontal wells drilled thought tight formations, including cores and well logs, is rather limited in most instances. It is concluded that the proposed method provides a useful tool for evaluation of direct sources of information that are available in many cases (drill cuttings) but are rarely evaluated quantitatively. The proposed method allows improved design of multi stage-hydraulic fracturing jobs in horizontal wells.