The Application Of Fluid Level Testing On Line Technology In Pumping Wells

In the process of development and production in oilfield, the fluid level is a very important parameter. Therefore, measuring fluid level and controlling depth of pump, which have crucial function in oil extraction process. These actions are effective ways to achieve stable operation of oil wells and increase in oil recovery efficiency. At present, the main method of fluid level measurement is using echo instruments, which include the conventional measurement calculating fluid level by the number of tubing couplings and the average length of tubing(Referred to as "coupling method").However, due to the couplings echo omissions and uncertainty of tubing length, these will result in a large measurement error. Timeliness and accuracy of measurement is difficult to guarantee and it is difficult to improve the efficiency of oil production.In recent years, a new type of echo instrument not only improves technology of air gun, but also makes use of components of the gas temperature distribution, heat capacity ratio, gas compressibility factor and other parameters in armulus between oil and casing, with which we could take advantage of Nolen empirical formula to calculate the speed of sound distribution. And then, according to the time interval during acoustic propagation, we could launch depth of fluid level(refeired to as "gas component method").Compared to the traditional "couplings method", gas component method" pays more attention to casing gas information during well logging and notice without regard to couplings number and tubing length. This new method has higher degree of automation and fluid level data measuring in real time is also guaranteed, which will improve the efficiency of oil production. This article is based on measuring principle of ”gas component method”, focusing on simulation under Matlab environment and calculation which contain temperature distribution of the associated gas and distribution of the speed of sound in the casing. Experimental results were compared with the measured data in a pumping well and we’ll analyze the differences finally. However, this method also has its shortcomings, due to the oil extraction process in a flowing bottom hole pressure near the surface temperature changes more frequently, which will affect associated gas components in casing.Automatic echo instrument is developed by RAG company which takes advantage of "gas component method" to measure fluid level accurately and in real-time. The instrument has achieved good results in the process of actual oil production, which not only promotes efficiency of oil extraction, But also possesses other functions like pressure buildup analysis in oil well in sucker rod pump.