渤海B油田胶质沥青沉积规律研究

Study on law of colloidal asphalt deposition in Bohai B Oilfield

胶质沥青质沉积对储层渗透率造成伤害,严重制约油田产能释放,及时判断是否存在沉积及其对产能的影响程度对油田生产开发具有重要意义。采用气-液-固三相平衡热力学模型,结合原油组分组成实验数据,判别渤海B油田容易发生胶质沥青质沉积。利用实际油田参数建立单井径向流模型,分析了胶质沥青质沉积与地层压力的关系,模拟了胶质沥青质沉积对产量的影响及储层伤害程度。研究发现:随着油田开发时间增加,地层压力逐渐下降,当压力下降到36~40 MPa时,胶质沥青质开始析出,当压力下降至28~33 MPa时,胶质沥青沉积速度加快,对储层渗透率伤害增大,产量大幅下降,胶质沥青沉积可使产量降低80%以上。

The colloidal asphalt deposition harms the reservoir permeability and seriously restricts the release of oilfield productivity.It is of great significance for oilfield production and development to timely judge whether there are the deposition and the degree of its impact on productivity.Based on the gas-liquid-solid equilibrium thermodynamic model and the experimental data of crude oil composition,it is concluded that colloidal asphaltene deposition is easy to occur in Bohai B Oilfield.A single radial flow model was established based on actual oilfield parameters;it was analyzed the relationship between colloid asphaltene deposition and formation pressure,and it was simulated the effects of colloidal asphaltene deposition on production and reservoir damage.It was found that the formation pressure gradually decreased with the increase of oilfield development time.When the pressure dropped to 36 to 40 MPa,the colloidal asphaltene began to precipitate.When the pressure decreased to 28 to 33 MPa,the deposition rate of colloidal asphalt accelerated,the damage to reservoir permeability increased,and the production decreased significantly,the colloid asphalt deposition reduced well production by more than 80%.