Propane-injecting shallow heavy oil reservoir exploitation method

Abstract

The invention relates to a propane-injecting shallow heavy oil reservoir exploitation method. The propane-injecting shallow heavy oil reservoir exploitation method includes the following steps: a horizontal injection and production well network is arranged in a shallow heavy oil reservoir exploitation area, an injection well and a production well are arranged in the oil layers at the same vertical plane position to form an injection and production well pair, the injection well is a horizontal injection well, the production well is a horizontal production well, and the horizontal injection and production well network comprises at least one injection and production well pair; injected steam circulation preheating is carried out simultaneously via the injection well and the production well; after the temperature of the oil layer between the horizontal section of the injection well and the horizontal section of the production well is increased to a predetermined temperature, the injection well and the production well simultaneously stop circulation preheating, propane starts to be continuously injected into the injection well, and the amount of the injected propane is 5000m3 / d to 25000m3 / d; and the production well starts continuous oil production. The propane-injecting shallow heavy oil reservoir exploitation method has the characteristics of high recovery rate, propane recycling, low exploitation cost, high economic benefit, low energy consumption, low emission, environment-friendliness and the like, and is easy and safe to operate.

Description

technical field [0001] The invention relates to a method for exploiting heavy oil reservoirs in oil fields, in particular to a method for exploiting shallow heavy oil reservoirs by injecting propane, and belongs to the field of oil exploitation. Background technique [0002] Heavy oil is the largest type of crude oil resource in the 21st century in the world. The world's total crude oil reserves are about 1.4-2.1 trillion tons, of which 70% are ordinary heavy oil, super heavy oil and oil sands. Heavy oil resources are mainly distributed in Canada, Venezuela, the United States, China and other countries and regions. my country's heavy oil resources are 18 billion tons, and the reserves are huge. Public information shows that the production of heavy oil and oil sands will reach 50% of the world's crude oil production in the next 20 years, becoming an important part of the world's energy supply. The world's major oil companies have taken heavy oil production technology resear...

AI Technical Summary

Problems solved by technology

But this method has three main problems: First, this method only provides air injection-assisted steam huff and puff recovery technology, but air injection-assisted steam huff and puff is essentially a pressure relief recovery technology relying on reservoir energy. Shallow heavy oil reservoirs have limited recovery due to low reservoir pressure energy; second, although this method is suitable for steam flooding, there is no mention of any technical measures to improve steam flooding heat utilization. Key technical issues such as reducing steam flooding heat loss; the third is that there is no explanation on how to control the injected air in the process of air injection-assisted steam flooding to avoid the safety hazard of oil-gas and oxygen mixture gas detonation

But this method has three main problems: one is that because super-heavy oil refers to crude oil with a viscosity greater than 50,000 centipoise of ground degassed crude oil, this patent application does not disclose the viscosity of the polymer gel formulation system, and public information shows (Hu Yong, Lu Xiangguo .Al prepared from sewage 3+ Performance characteristics of cross-linked polymer gel [J]. Oilfield Chemistry, 2004, 21 (4): 336-339): The viscosity of the polymer gel formulation system usually does not exceed 50 centipoise, so the injection fluid and oil The mobility ratio is above 1000, the swept volume of crude oil and the range of enhanced oil recovery under such high mobility ratio conditions are debatable; the second is that the application effect of the method for enhanced oil recovery is not mentioned in the disclosed examples of the patent application; The third is that the polymer gel stays in the oil layer and will cause environmental pollution

However, like the technical solution disclosed in CN101004132A, the method proposed in this patent application does not explain how to adopt control measures to avoid the potential safety hazard of the explosion caused by the front edge of the fire line breaking into the bottom of the production well

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