Optimized Well Path Planning Decisions in Real-time Monitoring Operations
Authors: Correa Born Christian , Ney Wilson Gomes , Falcone Celia Maria Oliveira , Lonardelli Josenilda Do Nascimento , de Lima Otavio Nunes Borges 
Published: June 2014

Enhanced collaboration between geologists, geophysics and drilling personnel, both onshore and offshore, can have significant positive impact, in terms of minimizing iterations in original well planning, improving well placement, reduction of uncertainties, risk-factors analysis, and studies of fluid losses and influxes, through common discussions during real-time operations. This paper discusses the benefits of real-time monitoring and integrating a multidisciplinary team with all related activities.

This work was performed in the Parque das Baleias area, south of EspÍrito Santo in Brazil. Most of the wells in this asset are complex, with nearly 1000 m of horizontal sections. Despite having an integrated seismic interpretation environment for well planning, the low quality of existing seismic data, along with related uncertainties, requires the asset team to make time-sensitive corrective actions to the well trajectory. The integration of real-time data not only helped to speed up existing iterations between geology/geophysics and engineering activities, but also allowed new and improved workflows to be implemented.

The observed results include better well placement and higher horizontal well net-pay penetration. It was clear to the asset team that the adoption of real-time monitoring helped to correlate all available information from different assets, contributing to a more comprehensive field development workflow, maximizing the development plan and asset performance. A common visualization environment can play an important role, enabling the asset team to develop more precise well paths and helping improve well-placement quality and the real-time decision making process. Finally, operational costs can be significantly diminished by the reduction of non-productive time (NPT) and avoidance of trouble events.

Introduction

Seismic subsurface imaging plays an essential role in geological interpretation and well planning, helping operators to predict unexpected drilling risks or unscheduled events. Drilling to reach complex reservoir targets requires several iterations between geoscience and drilling engineering, and better results are directly related to faster information exchanges between members of a multidisciplinary team. Drilling engineers and geoscientists often collaborate to discuss well planning, drilling of the actual wellbore, or any other field development activities. Real-time monitoring during a drilling operation can offer important tools to geologists and geophysicists to help confirm or forecast an event and enable interventions in the operation based on analysis of the acquired data. For directional drilling, the use of rotary-steerable systems has been crucial to improve the well placement. The existence of different workflows and applications of a particular database for each discipline can result in delays and inaccuracy. Integrated solutions in the same interpretation and visualization environment can speed up decision making for corrective actions without requiring intense manual effort.

Some uncertainties involved in this process are related to different information domains and data sources specific to each discipline. Integrating tools, uncertainties, risk factors, and objectives in a common visualization environment can be an important resource to enable the asset team to plan the well path using the same subsurface data. Because of the seismic data quality or resolution level inherent to a particular method, results can be considerably inaccurate. Velocity modeling and time-depth conversion are crucial steps for planning the well trajectory and confirming the results during a drilling operation, and they can be analyzed while drilling.