陕北低渗透裂缝性油藏调剖试验研究

Pilot test effect analysis of profile control for fractured low permeability reservoirs in northern Shaanxi

李宪文 郭方元 黎晓茸 王兴宏 谭俊领 徐春梅

LI Xianwen GUO Fangyuan LI Xiaorong WANG Xinghong TAN Junling XU Chunmei

低渗透油气田勘探开发国家工程实验室，陕西西安　710021 长庆油田公司油气工艺研究院，陕西西安　710021

Low Permeability Oil Field Exploration and Development National Engineering Laboratory, Xi’an 710021, China Oil and Gas Technology Research Institute, Changqing Oilfield Branch, PetroChina, Xi’an 710021, China

安塞油田三叠系长6储层渗透率（1~3）×10?3μm2，在92口见水油井中，裂缝型和裂缝-孔隙型见水油井29口。靖安油田三叠系长4+5储层平均渗透率1.447×10?3μm2，在68口见水油井中，见注入水油井41口，由于裂缝沟通，不少油井投产初期即见注入水；姬塬油田侏罗系延9油藏平均渗透率66.9×10?3μm2，吸水厚度仅占油层厚度的35%，部分油井水淹，而大部分油井注水不见效。通过对低渗透裂缝油藏调剖实验研究，确定采用体膨颗粒和聚合物弱冻胶复合调剖工艺，在实施调剖的20个井组中，有19个井组吸水指数明显降低；有11个井组取得了增油、降水效果；有5个井组含水率下降；有3个井组，由于裂缝封堵强度过大，导致调剖无效。

The Triassic Chang 6 reservoir in Ansai Oilfield is with low permeability((1~3)×10-3 μm2), and there are 29 oil wells with water breakthrough of fracture or fracture-pore type in 92 oil wells with water production. The average permeability of the Triassic Chang 4 and Chang 5 reservoir in Jing’an field is 1.447×10-3 μm2, and the produced water of 41 oil wells is injection water in 68 oil wells with water production. Some of the oil wells produced injection water at early time of production due to fracture communication. The average permeability of the Jurassic Yan 9 reservoir in Jiyuan field is 66.9×10-3 μm2, and the water intake thickness is only 35% of the total reservoir thickness. A part of the wells are watered out, whereas most of the oil wells have not take effect from water injection. Swelling particles and weak polymer gel were taken to conduct the profile control treatment. In the 20 profile control treated well groups, the injectivity coefficients of 19 well group were decreased significantly, 11 well groups obtained the effect of oil rate increase and water cut decrease, 5 well groups obtained water cut decrease, and 3 well groups was invalid for the profile control treatment due to too high crack sealing strength.