套损井原因分析及治理工艺

Casing Damage Analysis and Control Technology

吉林油田套管变形现象严重,套管变形率高达22%,每年还以100多口井的速度递增。套管变形和损坏造成的套管外返液,给环境带来了严重危害和不良社会影响。为此,对其采取了治理措施。主要治理工艺是:取出破损套管,更换新套管,实施机械封堵、化学剂封堵,从套管内及其上部射孔处注入水泥和堵剂。在吉林油田,应该科学合理地注水,提高固井质量,科学地计算地应力型地层,采用高强度厚壁套管,提高油层套管的抗外挤强度。

The casing deformation of oil well in Jinlin Oilfield often happened in recent years. The casings of about 100 oil wells were deformed every year. The deformation rate of casings is about 22 percent in the oilfield. The fluid overflow resulted from casing deformation or damage is seriously damaging to the environment protection and social safety. Some control measures for controlling the fluid overflow have been taken. The main control technologies include exchange of deformed casings, machine plugging, chemical agent plugging, injection of cement and plugging agent into formation from casing and the perforations at the top of casing. In order to avoid casing damage in Jilin Oilfield, it is necessary to inject water scientifically and enhance cement job quality. The ground stress of formation should be reasonably computed. The high strength and thickened casings should be adopted, and the casing strength resistant to external force in formation should be enhanced in this oilfield.