低渗透油藏二氧化碳分注工艺及配套测调技术

CO_(2) Separate Injection and Matching Testing and Adjustment Technologies in Low-Permeability Reservoirs

针对低渗透油藏CO_(2)驱笼统注气存在单层突进,吸气不均,部分储量无法动用等问题,研发了CO_(2)分层注入及配套测试技术。优选耐CO_(2)腐蚀橡胶,封隔器耐温120℃、承压35 MPa,形成了CO_(2)单管多层注气工艺。研制多级绕流气嘴,节流压差大于5 MPa,满足现场多层分注需求。研究实际工况条件下绕流气嘴特性,绘制图版指导现场测调,同时形成配套CO_(2)验封及分层流量测试技术,实现分层调配。该技术能够缓解层间矛盾,延缓气窜,提高薄差储层动用程度。

Regarding the problems encountered during general CO_(2) injection for low-permeability reservoirs,such as water excessive advancement along a single layer,uneven gas absorption and failure to produce some reserves,CO_(2) separate injection and matching testing and adjustment technologies are developed.With a corrosion-resistant rubber selected,the packer has a temperature resistance of 120℃,and a pressure resistance of 35 MPa.A single-pipe multi-layer technology is developed for CO_(2) injection.Multi-stage streaming nozzles are also developed.With a throttling differential pressure greater than 5 MPa,the nozzles can meet the demand for multi-layer separate injection in the field.By studying the characteristics of multi-stage streaming nozzles under working conditions,charts are plotted to guide field testing.In addition,matching CO_(2) sealing detection and separate-layer flow testing technologies are de-veloped to achieve separate-layer adjustment.With this technology and its matching technologies,inter-layer problems can be mitigat-ed,gas channeling can be postponed,and the production degree of thin and poor reservoirs can be improved.