鄂尔多斯盆地致密油滑溜水压裂液的研究与应用

Research and application of slippery water fracturing fluid for tight oil in Ordos Basin

 安杰¹ 刘涛² 范华波¹ 魏波² 何梅朋² 袁斌²

中国石油长庆油田分公司油气工艺研究院，陕西 西安 710021 中国石油长庆油田分公司第六采油厂，陕西 西安 710200）

Research Institute of Oil and Gas Technology, Changqing Oilfield Company, PetroChina, Xi′an 710021, China No.6 Oil Production Plant, Changqing Oilfield Company, PetroChina, Xi′an 710200, China)

 北美页岩气等非常规油气资源得到了效益开发，主要的增产手段是滑溜水体积压裂。国内致密油储层改造使用的滑溜水压裂液研究与应用较少，国外产品价格昂贵且技术封锁。鄂尔多斯盆地致密油资源量大，开发前景广阔，其储层条件更复杂，具有低孔、低渗、低压特点，使用常规压裂液改造施工压力高，储层伤害大，改造效果不理想。该盆地黄土塬地貌水资源匮乏，体积压裂备水困难，且大量的返排液增加了环保压力。根据致密油地质特征和工艺需求，合成了梳状分子结构减阻剂DR64，配套优选出高效助排剂和黏土稳定剂，形成了一种适合盆地致密油开发的低成本可回收滑溜水压裂液体系。大量的室内和矿场试验表明，该体系减阻率达到64.1%，有效地减小了高泵压的风险，具有低伤害、携砂性能稳定、低成本可回收重复利用的特点，表现出良好的工艺适应性，为国内非常规油气资源的开发提供了宝贵经验。

 Owing to the slippery water volume-fracturing stimulation, unconventional oil and gas resources such as shale gas have been effectively developed in North America. Few research and application have been carried out by slippery water for tight oil reservoir stimulation in China. Products with similar functions from abroad are costly and their techniques are closed to others. The huge amount of tight oil resources within the Ordos Basin creates a broad development prospect, however, low porosity and low permeability as well as low pressure make the reservoir condition more complicated. Conventional fracturing fluid can be used to improve reservoir quality, but it′ll lead to high pressure in renovation construction and great damage to tight oil reservoir, resulting in non-ideal effects. Furthermore, it is difficult to prepare enough water for volume-fracturing process because of barren water resource due to loess plateau landform. Also, vast flow-back fluid further boosts pressure to environmental protection. Based on geological characteristics and process requirements of tight oil, this paper introduces a low-cost and recyclable slippery fracturing fluid system suitable for the tight oil development in Ordos Basin, which is the synthesizing drag reducer DR64 with comb-like molecular structure. Efficient anti-swelling agents and clay stabilizers are optimized. A large number of indoor and field tests show that the drag reduction rate produced by this system reaches 64.1%, effectively lowering the risk of high pump pressure with low-damage, stable sand-carrying, low-cost, recyclable and reusable characteristics. This system proves to be a well adaptive technology, offering a valuable experience for domestic development of unconventional oil and gas resources.

10.6056/dkyqt201604029