Study Of Temperature Gradient Model Of Gas Injection Well Of SAGD And Temperature Monitoring System

Viscous crude oil is an important part of the hydrocarbon resources in the21stcentury. Entering the mid and late stage of our country’s crude oil mining, thedevelopment method by steam stimulation and steam drive has turned to SAGD.This method is asking more of the parameters achieved by temperature dynamicmonitoring of the wellbore. Through the continuous monitoring and analysising ofthe wellbore’s temperature, we can obtain the development situation of the steamcavity in a dimension of time and space. This is also the theoretical basis forjudging the connection of steam cavities. However, during the gas injection process,the conventional underground temperature detection method can’t meet therequirements of realizing steam temperature distributed real-time on-linemonitoring in tubing-casing annular space and perforated interval.This paper, which is based on the heat transfer principle, law conservationmass, law of conservation of momentum and law of energy conservation, startingwith formation temperature field model, established the calculation model ofpressure, temperature and heat loss model in the process of steam flow from mouthof a well to horizontal section. And do the research about the steam parameters withtime at the bottom of the well during the process of steam injection for heavy oil.Combine the vertical interval, deflecting interval, horizontal interval calculationmodel together to comprise the complete thermal production well temperaturegradient coupling model. Using the iteration method, by setting reasonable startingparameters, we get the entire temperature curve.For the special condition of steam injection wells, based on the anal ysis on theprinciples and advantages about the Raman fiber temperature sensing technology,this project decided to use Raman fiber optic sensor to build monitoring system; Forspecial condition of high temperature hydrogen loss, polyimide coated hightemperature optical fiber is chosen as the core of the original finally. Considered thecomplexity of the underground, the fragility of optical fiber and the possibility ofhydrogen loss, a reasonable packaging of the optical fiber was designed. Using ofheat transfer theory, the sensitivity analysis of the packaged optical fiber was made, and the performance of temperature sensor was shown though the experiments. Thedesign about the protection and positioning of this device is also made.Using of MATLAB to complete the calculation of the temperature gradientmodel about the process of steam flow from mouth of a well to horizontal section,this article got the whole wellbore temperature curve; Using of ANSYS temperaturefield analysis module to simulate the basic principle and model, and this articlevalidated the accuracy of the calculation model. Using the Raman fiber temperaturemonitoring system to measure temperature in wellbore during the process of steaminjection for heavy oil many times, this article analyzed the data to get temperaturechanging law in tubing--casing annular space. Compared oil fields data with thedata calculated by the temperature gradient model set up in the paper, this paperanalyzes the cause about the deviation of gradual warming area between oil fieldsdata with the data calculated, which testified veracity and reliability of theestablished model. Based on the established temperature gradient model, I analyzeeach note steam parameters’ effect on temperature curve, and try to mak eoptimization of each steam injection parameters, and improve the efficiency of thesteam injection. So that we can obtain ideal temperature at the bottom of a well inenergy saving.