多级加砂控缝高工艺技术在渤海油田压裂施工中的运用

Application of multi-stage sand adding and fracture height control technology in fracturing operation of Bohai Oilfield

在助力提高海上油气田增储上产的“七年行动计划”重要阶段,海上油气田低渗压裂项目正在按计划表推进。通过水力压裂工艺技术对低渗储层进行物性改造,为最大可能提高目标井的油气产量和稳产时间,在压裂规模论证阶段,一方面要尽可能地提高油井的压后产液量,另一方面要尽可能地降低油井产液的含水率,使压裂改造后的油井经济性最大。在压裂工艺设计先期阶段,为降低油井后期生产时的含水率,主要有2种途径。第一种是改造储层孔喉通道和人造裂缝通道的表面润湿性,使其增加地层水在储层孔喉和人造裂缝通道里的流动阻力,同时降低油气流的流动阻力,主要的措施手段有泵入堵水化学药剂和在裂缝中填充表面改性的控水支撑陶粒,但该途径控水效果有限且有效期较短;第二种途径是让人造裂缝定向延伸,避免沟通含水率较高的层位,主要的措施手段有射孔方案优化和多级加砂控缝高工艺技术。本文聚焦在控缝高工艺技术方面,通过泵注不同规格的支撑剂,在压裂施工阶段,避免裂缝向下延伸至底水,从而达到降低油井含水率的目的。介绍了此种工艺技术的设计基本原理、现场应用实例和效果追踪数据,为其他油田压裂项目的遇到类似问题时提供参考。

In the important stage of the“seven-year Action Plan”to help increase the production of offshore oil and gas reserves,low permeability fracturing projects in offshore oil and gas fields are progressing as planned.By hydraulic fracturing technique for low permeability reservoir physical property reform,for the greatest possible improving target wells of oil and gas yield and stable yield,during the fracturing scale argumentation stage,on the one hand,as far as possible to improve the well producing capacity,on the other hand,as far as possible to reduce the water producing,make the largest oil wells economy.In the early stage of fracturing process design,there are two main ways to reduce the water cut in the late production of oil Wells.The first is a transformation of reservoir pore throat channels and artificial fracture surface wettability,increase the formation water in the reservoir pore throat and artificial fracture flow resistance in the channel,at the same time reduce the flow resistance of hydrocarbon flow,main measures means of pumping water plugging and chemical reagents and filling in the cracks of the surface modification water control support ceramsite,but the way water control effect is limited and the period of validity is shorter;The second way is to make the artificial fracture directional extension to avoid communicating with the layer with high water content.The main measures include the optimization of perforation plan and the multi-stage sand adding technology to control the fracture height.In this paper,we focus on fracture-controlled high technology by pumping different specifications of proppant to prevent the fracture from extending down to the bottom water during the fracturing phase,thus achieving the goal of reducing the water content of the well.This paper introduces the design principle,field application example and effect tracking data of this technology,which can provide reference for other oilfield fracturing projects when they encounter similar problems.