Research On The Prediction Of Scaling Tendency In Gathering And Transportation System Of Multi-Department

In order to make underground resources got extract adequately and enhance the crude oil recovery, multi-layer unite exploitation has become the trend of oil extraction. For the different formation ages of different oil reservoir, the crude oil and produced water exploited from the multi-layer unite exploitation are highly variable in nature. When the oil-water or gas-water from two or multi-pipelines is mixed, that scale is easily formed in the valves installed at the junction of the pipelines because the oil-water or gas-water from two or multi-pipelines is not compatible with each others.This paper examines scaling mechanism, analyzed the principal compositions of the oil field water, the main factors of effect scaling and the easily scaling location for ground gathering systems, and studied various predicting methods of scaling of field water and formulas of temperature drop and pressure drop for oil-gathering system. On account of the analysis of water samples from several oil fields of Changqing oil field, this paper puts forward five major factors, including salt content (Ca²⁺,Ba²⁺,Cl^-,SO₄^2-,HCO^3-and so on), temperature, PH, ratio and pressure, and established scaling prediction model for multi-layer oil-gathering system. Use the Davis and Stiff index of saturation to predict the scale formation of calcium carbonate, the OT index of saturation to predict the formation scaling trend of sulfate, and max amount of scale predicting equation to predict the seriousness of the scaling. That three categories above formed the model of trend prediction of scaling, also established the model of location prediction of the scaling linking with the formulas of temperature drop and pressure drop for long-distance pipeline. In the end, a software program of scaling prediction for the multi-layer mix oil-gathering system of Changqing oil field was worked out. The program developed in VS2008 environment, adopted a design method of face to the object, and is a NET application developed in WINDOWS XP environment. Adopt event-driven programming control, WINDOWS general interface, with simple operation and high degree of reliability. The software focuses on the prediction of inorganic scale formed by different types of oilfield water in oil-gathering system of oilfield. It can predict the type, trend, degree and location of the inorganic scale.