长庆油田水平井套中套井筒再造体积重复压裂技术

Casing-in-casing wellbore reconstruction and volumetric refracturing technology of horizontal well in Changqing Oilfield

王飞 慕立俊 陆红军 白晓虎 卜军 任佳伟

WANG Fei MU Lijun LU Hongjun BAI Xiaohu BU Jun REN Jiawei

中国石油长庆油田分公司油气工艺研究院 低渗透油气田勘探开发国家工程实验室 中国石油长庆油田分公司

Oil & Gas Technology Research Institute, PetroChina Changqing Oilfield Company, Xi'an 710018, Shaanxi, China National Engineering Laboratory of Low-permeability Oil & Gas Exploration and Development, Xi'an 710018, Shaanxi, China PetroChina Changqing Oilfield Company, Xi'an 710018, Shaanxi, China

长庆油田超低渗透油藏部分水平井初次改造程度低，前期先导试验攻关形成了水平井双封单卡体积压裂技术，然而双封单卡工艺存在起下钻次数多、放喷时间长、管外窜等问题，严重制约现场施工效率。通过压前补能、凝胶降漏、下入Ø114.3 mm套管、热固树脂环空封固等技术重造新井筒，评价储层增产潜力，优化新老裂缝布缝与裂缝参数，配套研发小直径可溶桥塞，形成了水平井套中套井筒再造重复压裂技术。在CP50-15井进行了现场试验，成功下入1500 m Ø114.3 mm套管并进行了环空封固，固井质量良好，采用桥射联作压裂工艺完成了26段压裂，施工效率达到了3段/d，投产后控制放喷生产，日产油由1.9 t升至15.4 t。该技术对提高超低渗透油藏采收率提供了新思路。

Some horizontal wells in the ultra-low permeability oil reservoirs of the Changqing Oilfield have low first stimulation degree, and the double-packer one-layer volumetric fracturing technology of horizontal well was researched and developed in the early pilot test, but the double-packer one-layer process faces the problems of multiple trips, long blowout time, and channeling outside casing, which seriously restrict its field construction efficiency. In this paper, a new wellbore was reconstructed by means of prefrac energy supplement, gel based circulation loss reduction, Ø114.3 mm casing, resinoid based annulus sealing, the reservoir production increase potential was evaluated, fracture deployment and fracture parameters of old and new fractures were optimized, and the small-diameter soluble bridge plug was developed, so as to form the casing-in-casing wellbore reconstruction and refracturing fracturing technology of horizontal well. It was tested on site in Well CP50-15, where 1500 m Ø114.3 mm casing was successfully run into the hole and the annulus was sealed, ensuring good cementing quality. 26-stage fracturing was completed by using the plug-perforating combined fracturing process, and the construction rate was 3 stages/d. After it is put into production, the controlled blowout production is carried out, and the daily oil production rises from 1.9 t to 15.4 t. This technology provides a new idea for the EOR of ultra-low permeability oil reservoirs.

10.13639/j.odpt.2023.01.012