Research On Depth Profile Control Optimization Technology Under The Condition Of Suitable For Sewage Of Chaoyang Ditch Oil Field

In this paper, profile control technology optimization laboratory research is carried outunder the condition, through experiment profile control agent formulations for the reservoirproperty and reinjection water quality of Chaoyanggou oilfiled are screened, to meet theneeds of the sealing fractures and high permeability layer gel viscosity. According to thechange of oil field at present well pattern in different areas, optimized the profile controltechnology parameters, provided feasible technology which stabilizing oil production andcontrolling water cut, increasing recoverable reserves for oilfield.Firstly, researched on the various components of the original formula through theexperiment, determined the composition of the system, there are polyacrylamide, chromiumtrichloride, lactic acid, thiourea and NaOH.Secondly, analysised of sewage quality, including research on Na⁺、Mg²⁺、Ca²⁺、S^2-、salinity and the oil content of sewage, indicates that the main factors affecting Gelling aresalinity of sewage and solution pH; studied on various factors of the gel system, determinedthe appropriate concentration range of components, the optimization formula of gel system isgiven; the molar ratio of chromium trichloride and lactic acid is1:8, the concentration ofHPAM is2000mg/L, the concentration of crosslinking agent is200mg/L, the concentrationof thiourea is800mg/L. The cost of the original formula quite.Then, evaluated the performance of gel system, through the core plugging experiment,oil displacement experiment and the stability of gel system, the plugging rate of gel system is81%-84%, the recovery increased5.3-9.1%after plugging; the gel validity is more than3months; the viscosity retention rate reached70%-80%at the end of validity. The range ofenhanced recovery after gel plugging in natural core between5.3-9.1%, the effect is good.After gel plugging, in high and low permeability parallel cores about80%of the flow comesfrom the low permeability cores, the vast majority of oil comes from low permeabilitycore（matrix core）, the recovery increased by15.53%, the effect of profile control is obvious.Finally, through studying the numerical simulation, optimized the profile controlparameters. When the gel injection is0.04PV, the flooding control effect is better; the effectof profile control timing on terminal oil recovery is small, the earlier profile control, thebetter; the whole injection is better than partial times injection. Thereasonable profile radiusof60m and40m and30m corresponding to the different well spacing of300,210,150mrespectively, reasonable concentration of2880m3,1410m3and720m3respectively. Research results provides a formula and key construction parameters for field test.