Method for determining influences on gelling property of fracturing plugging agent by different molecular weights

Abstract

The invention discloses a method for determining influences on a gelling property of a fracturing plugging agent by different molecular weights. The method comprises the following steps: (a) preparing fracturing plugging agent solutions with different molecular weights at room temperature; (b) then, adding a cross-linking agent and an accelerating agent; (c) standing for a period of time and measuring a system viscosity of the fracturing plugging agent; and (d) analyzing the influences on the gelling property of the fracturing plugging agent by different molecular weights through a tested result. According to the method disclosed by the invention, the influences on the gelling property of the fracturing plugging agent by the different molecular weights can be rapidly detected; and the tested result is accurate, the testing step is simple and the testing cost is greatly reduced, and the method provides data support to the utilization of the fracturing plugging agent.

Description

technical field [0001] The invention relates to a method for measuring the influence of different molecular weights on the gelling performance of fracturing plugging agents. Background technique [0002] Low-permeability reservoirs in my country generally refer to reservoirs composed of oil layers with a permeability between 10-50×10-3μm2. With the continuous deepening of exploration and development, my country's low-permeability oil reservoirs account for an increasing proportion of the total proven reserves and produced reserves, and play an increasingly important role in maintaining and promoting the development of the petroleum industry. Big. Take China National Petroleum Corporation as an example. By the end of 2001, the proven oil reserves in place were 145×108t, of which low-permeability reserves were 44×108t, accounting for 30%; the produced oil reserves were 110×108t, of which low-permeability reserves were 21×108t , accounting for 19%; the remaining proven undevel...

AI Technical Summary

Problems solved by technology

[0004] (1) The natural production capacity of the oil well is low, and it has industrial exploitation value only after fracturing;

[0005] (2) The law of seepage does not follow Darcy's law and has a starting pressure gradient;

[0006] (3) The natural energy is small, the pressure and output drop rapidly, and the primary recovery rate is low;

[0007] (4) The water absorption capacity of the water injection well is low, and the starting pressure and water injection pressure rise rapidly;

[0008] (5) The liquid production index of the oil well drops sharply after water breakthrough, making it very difficult to stabilize production

[0010] Oil, gas, and water wells after hydraulic fracturing, due to the limitations of fracturing technology, materials, equipment and tools at that time, were small in scale, improperly selected materials, and limited equipment power, etc., would lead to a significant reduction in the conductivity of hydraulic fractures and gradually Some of them are not effective due to improper well layer selection or operational reasons. At the same time, after long-term development, major oil and gas fields have entered the development stage of medium and high water cut periods, and it is becoming more and more difficult to achieve high and stable production. For this type of oil and gas Wells that require refracturing for high production and economic recovery

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