The Study And Application Of High Temperature Profile Control And Oil Displacement System Of Qi 40 Steam Drivereservoirs

Liaohe Oilfield in Qi 40 block is the first deep heavy oil steam flooding pilot test block. Compared with other heavy oil reservoir at home and abroad, the reservoir is buried deeply, about 622 m~1050 m,therefore the experience of steam drive that can be referred is not enough, problems occurred in the project need be urgently solved by independent thinking. Under this background, according to steam flooding reservoir characteristic and steam flooding development status of steam early breakthrough and the serious steam channeling of Qi 40 block, this paper carry out the high temperature of deep profile control and oil displacement agent in laboratory research and field application technology research, initially formed a set of applicable technology in Qi 40 block steam flooding reservoir with high temperature deep profile control and flooding technology.In this paper, we selected the CX-4 foaming agent that can bear the high temperature of 270 ℃, foaming agent concentration(0.3% ~ 0.5%) is best. Through analysis laboratory synthesis of wood element surface active agent infrared spectrum graph shows the sulfonated product characteristics. Analysis of UV spectrum diagram shows the solution contains more symmetry of springy benzene ring structure, these properties show that synthetic paper wood surfactant products to high temperature and thermal recovery conditions used.In this paper, through the laboratory experiment study to determine the steam flooding high temperature deep profile control and displacement: 0.3% oil displacement agent formulation(weight percentage) flooding(CRF) + 0.5% foaming agent(CX-4), laboratory physical simulation experiments show that use of profile control and oil displacement agent recovery rate increased significantly.This paper found that the main reasons of affecting the steam channeling of Qi 40 block steam flooding is the three factors, the rhythm of reservoir, the dip of structure and the physical property of the reservoir. The research shows that: reverse rhythm reservoir vertical steam overlap caused by the top of the steam channeling; composite rhythm reservoir hypertonic zone caused by layer subentry banded steam channeling; the structural high part of the edge of the well, due to the lower part of a steam injection can cause parts of the high overlap steam channeling; inverted nine spot well network angle well generally no steam channeling or steam channeling slightly.Through the research, it is obtained that the optimum design result of the high temperature deep profile control and displacement reservoir engineering in Qi 40 block steam drive oil reservoir:(1) Well type: inverted nine-spot injection pattern;(2) Perforation scheme: the lower reservoir hole filling, sealing packer machine card sealing oil layer in the upper perforation interval, steam not be injected into the original perforating zone, and only injected steam into the lower reperforate zone;(3) Injection production parameter:Foaming agent concentration: the initial 500 days using the foaming agent concentration 1.5%, 500 ~ 1450 days of the foaming agent concentration of 1.0%, after 1450 days the foaming agent concentration of 0.5%;Gas liquid ratio: the ratio of gas to liquid ratio is 1.0;Injection ratio: about 1.2;(4) The injection mode: after continuous air foam assisted steam flooding for 1 year, turned to alternate slug continuous injection for every 10 days.Using the above optimized design results, the development index of the air(nitrogen) foam slug in the test area was developed. Prediction results show that: the economic and effective production time of 8 years, the cumulative injection steam 60.19 million tons, the cumulative injection of air 946.96×104 m3, cumulative fluid 134.62 million tons, cumulative production of air 691.40×104 m3, cumulative oil production of 26.58 million tons, in the steam flooding stage based on the recovery degree was 21.91%, and currently steam huff and puff + drive stage recovery degree was 49% and the ultimate recovery rate can reach 70.91%, plan final production yield was 61%, so the air(nitrogen) foam slug assisted steam flooding, oil recovery than the original design high out 9.91%.In this paper, the problem of uneven steam injection profile in the late stage of the steam drive in Qi 40 block is studied thoroughly, and the large dose deep profile control agent for steam drive reservoir is developed. The formula of high temperature deep profile control system for steam drive reservoir is developed:(1) Inorganic resin high temperature profile control agent. The system formula is: the concentration of the resin 15-20% + the concentration of the crosslinking agent 8-10% + the concentration of the inorganic substance 15-20%, and the working fluid viscosity of the high temperature profile control agent 70-100 m Pa·s to control the water content.(2) High temperature three phase foam profile control agent. The system formula is: 0.8% polyacrylamide + 0.4% crosslinking agent + 0.25% heat stabilizer, working fluid viscosity 100-200 m Pa.s to control the amount of water. The proportion of lignin fiber, composite resin and CX-4 foaming agent in the system was 3:1:0.5, and the total amount of the solid phase was 1%-8%.In this paper, two kinds of deep profile control technology are proposed for the requirement of different well conditions in Qi 40 block of steam drive. This technology is not only provides favorable conditions for subsequent deep flooding, but also as a unique production technology for Qi 40 block steam flooding application test, obtained the input-output than 1:4.5 of good results. Indicating that the new technology has better popularization and application value.