氮气泡沫在塔河强底水砂岩油藏的应用

Application of Nitrogen Foam in Sandstone Reservoirs with Strong Bottom Water in Tahe Oilfield

塔河油田砂岩油藏具有强底水、埋藏深、温度高、矿化度高等特点,强底水是其主要特征之一。为了探索此类油藏治理方案,2014年在塔河油田二区东区块和塔河九区三叠系油藏进行了氮气泡沫吞吐、调驱技术的应用。氮气泡沫技术是通过向油井中注入氮气,同时注入泡沫剂,改善调剖、驱替能力,对边底水油藏压水锥、提高采收率。现场进行了TK907H、TK923H两口井的单井吞吐试验和TK202H井组调驱试验。试验结果表明:TK907H井组驱替效果优于单井吞吐效果,TK923H井单井吞吐效果不明显,这俩井组累计产生费用273.5万元,增油4942.7t,折算吨油成本553.3元/t;TK202H井组三轮次氮气泡沫驱替累计产生费用377.1万元,增油1132.6t,吨油成本3329.5元/t,氮气泡沫体系的适应性、有效期有待进一步提高。

The sandstone reservoirs in Tahe oilfield have the characteristics of strong bottom water ,deep buri- al depth,high temperature and high salinity.In order to explore the development plan for this type of oil reservoir, nitrogen foam stimulation and technology of profile modification and oil displacement were applied in Triassic reservoirs of eastern block 2 and block 9 in Tahe oilfield in 2014.The technology of nitrogen foam is： the ability of profile modification and oil displacement may be improved,and water coning may be con- trolled and oil recovery may be enhanced in the oil reservoirs with edge and bottom water through injection of nitrogen and foam agent at the same time to the oil well.Huff-puff experiments for single well were made in wells TK907H and TK923H, and experiment of profile modification and displacement was made in TK202H well group in the field.The results present that the displacement effect in TK907H well group was better than the stimulation effect of single well.The effect of the huff-puff for single well was not obvious for well TK923H.In these two well groups,cumulative costs were 2735 thousand yuan,and incremental oil production was 4942.7t,which may be converted to 553.3yuan/t of the cost per ton;In TK202H well group,the cumula- tive costs of the nitrogen foam displacement by three cycles was 3771 thousand yuan,and incremental oil production was 1132.6t,which may be converted to 3329.5yuan/t of the cost per ton.Adaptability and validity period of the nitrogen foam system should be improved further.