Novel Drilling Engineering Methodology to Enhance Wellbore Positioning and Performance Using Disruptive MWD/LWD Technology

Abstract

Abstract The Llanos basin is one of the most important areas in Colombia, due to its contribution to the national oil production and the development plans managed by operator companies. The projects in llanos basin face different challenges such as heavy oil production, low reservoir thickness, lateral variations, active aquifers, and low resistivity contrast of its fluvio-estuarine sands. These circumstances demand the design of complex horizontal profiles, being the TVD definition and well placement paramount to land and maintain the trajectories in the sweet spot. This paper shows how the application of disruptive Measurement while drilling (MWD) and logging while drilling (LWD) technologies with the support of novel drilling engineering methodologies, permitted to reach difficult reservoirs and maintain production in Ocelote, Guarrojo and Pintado fields, with a positive outcome in drilling performance and sustainability. The key actions for the mentioned success, described in this paper, were:Introduction of a disruptive MWD technology to enhance the true vertical depth (TVD) definition in the 8 ½" landing section using the Definitive Dynamic Surveys (DDS) capability of the tool combined with a new methodology to define the optimum survey frequency while drilling.Optimized positive displacement motor (PDM) bore hole assemblies (BHAs) and fit-for-purpose drill string configurations leveraged in an engineering procedure that maximizes weight transfer to the bit and avoids buckling.Digital enabled workflows to perform well planning and engineering calculations.Introduction of an LWD technology that provides an outstanding definition of the resistive channels in the sands, managing to map and define zones with less than 4 ft TVD thickness. The new survey methodology permitted the capture of an optimum amount of data in the landing section which enabled a more accurate TVD calculation, decreasing the uncertainty in the structural model, and improving the correlation for future wells. In addition, the drilling dynamic survey saved up to five minutes per stand reducing also the differential stuck pipe risk. The deep azimuthal resistivity technology successfully mapped multiple layers despite their low resistivity contrast, clearly differentiating their resistive properties to support real-time proactive decisions and augment the production well after well. In the last two years, there has been an increase in net pay from 65% to 80% (Average) along with a 30% increase in the length of horizontal sections thanks to the implementation of these technologies. The complex well profiles drilled in the past with rotary steerable systems now are possible with the optimized motor BHAs. From the operator's perspective, the optimum trajectory design and precise placement of the wells have permitted draining reservoirs in a more effective way increasing the project profitability. The methodology designed to define the optimum survey frequency, by taking advantage of the definitive dynamic survey technology, represents a new approach to improve TVD definition in the industry without incurring extra data processing or additional parts in the survey program. The BHA design process permitted drilling efficiently, being this technique a didactic reference for horizontal or high inclination wells. The novel multilayer mapping-while-drilling technology used can be applied in thin reservoirs with similar conditions.