Published: 09/27/2018
Published: 09/27/2018
After findings were made in the presalt province that represented a major discovery for the oil industry, drilling activity in Brazil has been focused primarily on economically viable ways to develop these reserves. Each day, new wells are drilled in ultradeep water through thick sediment layers and homogeneous or heterogeneous salt formations to access these reservoirs. The presalt cluster is a geological formation that consists of organic microbial carbonates and other sediments. The reservoir poses innumerous drilling challenges, including hard silicate nodules and low-porosity layers, which make the formation strength extremely high. Also, the heterogeneity level of such carbonates (within centimeters) imposes extra challenges, especially on drilling shock & vibration, with low rates-of-penetration (ROP), raising presalt well construction costs. In a best-case scenario, the industry strives to complete the entire well section in one run without interference or unexpected events. The development and use of new technologies to drill the reservoir section with high efficiency and low cost is essential. To offer a technical solution, the service provider applied an innovative bit design, modelled for cutting structure resistance, stability, and aggressiveness delivering higher ROP. Along with the technology, a new workflow called “stratigraphic zonation for drilling” was implemented. Using this concept, a model based design approach was put in place to optimize drilling performance and help product development. This article reviews the work covering this new cutting element technology, the development of this virtual drilling scenario and some field results with lessons learned and way forward.