Menggulin Reservoir Movable Gel Profile Control Experiment Studies

Weak gel is composed with low concentration polymer and crosslinking agent, in which the intermolecular crosslinking is mostly. In porous medium, it is ease for it to enter in to high permeability zones with high capacity channel, while it is hard for it to enter into low permeability layers, which indicates that weak gel can enter into heterogeneous lays selectively and have a seepage nature. It is an important technique in TOR, because it has dual effects that are in-depth profile control and oil displacement. For attaining the purpose of the control, it's very important that screening and laboratory evaluation in consideration of the reservoir condition.On the basis of refering to a number of documents, it is generalized which includes components of weak gel, displacement mechanism of weak gel, development history and tendency of weak gel, influential factors of gelling and laboratory evaluation approaches, etc. In regard to the condition of Menggulin fault block oil reservoir, an optimization in laboratory of weak gel system formulae was launched, then a set of gel system suiting for Menggulin oil field has been developed.In view of that well wellhead samples can't gelation in some injection wells of Menggulin oilfield Shaxi block, it has been found that the main gelling factor is valve throttle, the affection of Fe²⁺, mechanical shearing and porous medium shearing is relatively smaller in laboratory.By means of changing the system parameters'such as polymer crosslinker ratio, polymer molecular weight, polymer concentration, B agent concentration, etc, gel system formulae are optimized further. Considing of gelation time, strength and stablity together, then recommending gel system formula for Menggulin oilfield is:polymer EORPAM-3 concentration 800～1000 mg/L, polymer crosslinker ratio 30:1, B agent concentration 300 mg/L.