渤海油田蒸汽吞吐试验井注汽压力影响因素分析

渤海海上油田蒸汽吞吐试验井A1井第一轮出现注汽压力高,注汽能力受限,热损失大,井底注汽干度没有达到预期,影响热采效果。为了降低注汽压力,改善蒸汽吞吐实施效果,采用正交试验方法对蒸汽吞吐试验井A1井注汽压力高的原因进行分析,认为影响A1井注汽压力高的敏感因素按影响程度依次是地层能量、渗透率以及原油黏度。该区块后续热采实施应先冷采降低地层能量或注汽前采取降黏增注预处理措施,以改善注汽实施效果。研究结果可为全区热采实施及类似油田热采开发提供指导。

Analysis on Influencing Factors of Steam Injection Pressure in Huff and Puff Test-well in Bohai Oilfield

The first cycled steam huff and puff test-well A1 in Bohai Oilfield appeared the difficulties of injection capacity limitation and high thermal loses. The steam dryness in bottom well didn't reach the expectation, which affected the thermal recovery effect. In order to reduce the steam injection pressure and improve the effect of steam stimulation, the orthogonal experimental method was applied to analyze the reasons of high steam injection pressure in test-well A1. The results indicated that the sensitive factors influencing the well A1 high injection pressure were successively stratum energy, formation permeability and oil viscosity. To improve the effect of steam injection, cold mining or the pre-treatment measures of viscosity reduction and injection enhancement should be taken before steam injection to reduce the formation energy. The research results can provide guidance for the subsequent thermal implementation in this block and the development of similar oilfields.