Development Of Mud Logging Quantitative Degassing System

Mud logging technology is timely and accurately on-line detection analysis of the content of hydrocarbon and non-hydrocarbon gases carried by drilling fluid in the process of oil and gas exploration,which is the key technology for discovery and evaluation of oil and gas layer.The conventional gas logging system has three parts including well site degassing,sample gas delivery and chromatographic analysis.The traditional gas logging technology normally can only separate and transfer 1 5C C component,which is restricted by drilling fluid temperature and environmental pressure.However,the heavy hydrocarbon component which can reflect the seismic information on reservoir properties and hydrocarbon cannot be analyzed online due to the current technology constraints,and it has great impact on the oil and gas zone evaluation and the judgment of the stratigraphic position.This article proposes a design scheme of a new type of quantitative degasser system for drilling fluid combined with the conditions of well logging site and essential requirements of heavy hydrocarbon component separation and transfer,based on the research of domestic and international development of gas logging degassing system.On the basis of drilling fluid drainage,heating and stirring,we implemented constant temperature and pressure control to the separation chamber and increased degassing ratio and interpretation and evaluation efficiency of the drilling fluid.We designed the control system for high-precision data acquisition and effective control to the electrical machine and heater,and compared the improved PID with conventional PID control algorithm based on MATLAB simulation model.Under the Keil C51 development environment,we compiled the procedure which achieved the collection of field sensor analog quantity and the control of proportional valve based PID control algorithm.Designed and developed control center management software based on VS2010 for monitoring the well site parameter and managing the operation condition of the degasser,the software communicates with SCM through serial port and with well logging server via TCP/IP.The overall tests in the laboratory and well site were conducted,upon the completion of the construction of hardware platform and the debugging of software.The experiments confirmed the feasibility of the design and realized the quantitative degassing to the drilling fluid.The desired design objectives were fulfilled and degassing efficiency was improved.