基于仿生蛇提高缝洞型油藏开发效果机理研究

Fractured-vuggy carbonate reservoirs owns nearly half of the total oil and gas reserves in the world, however, these reservoirs are hard to be exploited and have a low recovery rate as a result of oil exploration inaccurate and drill in point uncontrolled.This project proposes a new mechanism including making quantitative exploration on the internal structures of Fractured-vuggy carbonate reservoirs with the use of snake-like robot, locating the well on the top of reservoirs precisely and improving reservoir exploring efficiency through oil substitution by water injection. This mechanism cannot only overcome the puzzles in the traditional method of water injection which encompass failure in crude oil exploration above the drilling point and void water recycling, but also overcome the deficiencies in low air injection safety and poor economy.The intended research solutions are combination of fluid-structure interaction with real objects tests. Based on fluid-structure interaction characteristics of crude oil in Fractured-vuggy carbonate reservoirs, we plan to analyze the shape change rule of between bionic snake and crude oil fluid, study the change rules between the shape of snake like robot and crude oil in Fractured-vuggy carbonate reservoirs according to the snake's force conditions exerted by the crude oil, then make clear of the main affecting factors on snake-like robot’s movement in crude oil, and finally simulate the exploring process of snake-like robot in crude oil with the aid of the Immersed Boundary Method- Lattice Boltzmann Method and crude oil fluid mechanics model.

缝洞型碳酸盐油藏占世界油气资源总储量的一半，由于勘探不准和油井钻遇点位置不可控等原因，普遍存在开采难、采收率低的问题。本项目提出利用仿生蛇对油藏内部结构进行定量勘探，准确地将井眼定位在油藏溶洞顶点上方，再结合注水替油方式来提高油藏开发效果的全新机理。该机理不仅可以克服传统注水方式无法开采钻遇点以上原油和无效水循环的难题，而且可以克服注气方式安全性和经济性差的缺点。研究途径拟采用流固耦合建模仿真与实物试验相结合的方式，以缝洞型油藏原油流体力学特性为基础，分析原油的受力情况、运动规律、粘度变化规律等，以仿生蛇受缝洞型油藏原油流体的受力情况为基础，仿生蛇与原油流体之间的形状变化规律等，明确影响仿生蛇在原油中运动的主要因素，最后结合浸入边界-格子Boltzmann控制算法与原油流体力学模型，模拟仿生蛇在原油中的勘探过程。本项目的实施，可望探索出仿生蛇在高粘度原油中的最佳运动方式和勘探过程，为实现提高缝洞型油藏开发效果奠定理论和试验基础。

缝洞型碳酸盐岩油藏资源储量丰富，但普遍存在开采难度大、开发效果差的问题。为了提高缝洞型油藏资源的采收率，本基金项目提出利用仿生蛇机器人对油藏内部结构进行定量勘探，准确地将井眼定位在油藏溶洞顶点上方，同时结合注水替换方式来提高油藏开发效果的机理。该机理不仅可以克服传统注水方式无法开采钻遇点以上原油和无效水循环的问题，而且可以克服传统注气方式安全性和经济性差的缺点，从而显著提高油藏采收率和开发效果。这种定量勘探对地下资源的发现具有十分重要的科学意义，对地下资源的精准高效开采具有广阔的应用前景。本项目主要采用流固耦合建模仿真与实物试验相结合的方式，通过模拟仿生蛇机器人在高粘度原油中的运动方式和观测在高粘度原油中的机动效果等研究手段，开展仿生蛇在缝洞型油藏原油流体中的流固耦合特性、仿生蛇在高粘度原油中的运动机理和运动能力等方面的研究内容，为实现基于仿生蛇提高缝洞型油藏开发效果奠定理论和试验基础。