A SCADA By-Pass Method to Bring Fiber-Optics Distributed Temperature and Reservoir Pressure Data to Reservoir Engineers!
Authors: Chaudhary Ashish , Maguet Philippe , Naveda Graciela Eva , Leimin Zhang , Zhi Kueh Jing , Hamid Afiq B.A. 
Published: May 2016

Many remote well locations have access to little electrical power available and limited telecommunications infrastructure. In these circumstances, collecting and transmitting critical growing volumes of critical reservoir or production data can be slow, costly and sometimes mobilization risks involved to personnel, especially during tough weather seasons. A need exists for a data acquisition and transmission system that enables high-rate data to be collected, compressed and transmitted in real time to the operator's office in a time reduced, cost-effectively and safely.

In Malaysia, some unmanned offshore platforms at mature stages of production required reliable well data to support simulation models, advanced reservoir studies, and committed production objectives. The platforms had limited power and communication capabilities. The traditional method of data collection required company staff to travel to the remote offshore site. Not only was this method dangerous due to the bad weather conditions, it also led to unpredictable and irregular data gathering frequency.

Hence an alternative method was developed where by numerous wells were instrumented with permanent downhole gauges (PDGs) and a few fiber-optics distributed temperature sensors (DTSs) to provide subsurface measurements of pressure and distributed temperature profiles along the wellbores A lightweight and smart piece of hardware at wellsite, collected automatically key data and in real time from remote terminal units (RTUs) located at the surface on the remote offshore platform. Data were then compressed applying mathematical algorithms and transferred over a broadband satellite network to a landing server located at town office where it was stored. All historical trends could be retrieved manually through a user-friendly web application. Alternatively the recorded data could be handled automatically by a customized data handling system, which worked on synchronizing the measurements data from the landing server to the production surveillance platform or reservoir data interpretation and modeling software. The entire system worked autonomously and could be remotely managed from anywhere through the corporate IT network. Rich connectivity options such as BGAN, 3G or WiFi were provided by the collection device.

Use of this data collection and transmission method reduced staff trips to the platforms and resulted in better, more complete and systematic data gathering. The system is affordable and scalable, fits easily into existing infrastructure, and brings together data from many different sources into an easy-to-understand, web-based interface.

Introduction

Transmitting high volumes of data from unmanned platforms offshore Malaysia demanded a simpler and more cost effective system. A user- friendly data transmission system that could be installed in parallel with existing infrastructure was required especially for brown fields which need low cost optimization techniques.

The project started in 2007 by investigating requirements in different parts of the world. The main challenge was to transmit data using flexible, modular, low-footprint software and a hardware-agnostic system. The initial goal was transfer of downhole pressure and temperature data from platforms or pads with limited connectivity (e.g., satellite) and with low power (e.g., from solar panels) to the office in town. No off-the-shelf system integrating hardware and software was available at the time; most data delivery solutions were extremely complex, expensive, or labor-intensive. The system described in this paper is today installed worldwide, connecting many diverse devices, handling high volumes of data using standard protocols, and incorporating user-friendly visualization tools.