CN101434835B - Preparation of jelly glue dispersion for oil reservoir deep liquid diverting - Google Patents

Abstract

The invention provides a preparation method of a jelly glue dispersion in-depth fluid flowing diverting agent, comprising the specific steps as follows: during a process when the jelly glue is formed by mixing part of hydrolyzed polyacrylamide and chromium acetate, a peristaltic pump applies a certain shearing force to a gelation system so as to lead the gelation system to form the jelly glue dispersion rather than integrated jelly glue. The jelly glue dispersion prepared by the method consists of jelly glue particles and water; and the particle diameter of the jelly glue dispersion can be controlled by adjusting the shearing speed. The jelly glue dispersion can be injected into the in-depth reservoirs; the adsorption and detention of the jelly glue dispersion particles in the hole can reduce the permeability of the high-permeability area, leads the subsequently injected liquid to be turned to the low-permeability area, and has the function of in-depth profile modification. The in-depth fluid flowing diverting agent has the advantages of low viscosity, good fluidity, good stability, long validity period, and the like, is insensitive to shearing and physical and chemical conditions of the reservoir, has controllable dimension, can design the diameter of the jelly glue dispersion with the aim of different stratums, and prevents blocking the stratum percolation surfaces.

Description

A kind of frozen glue dispersion preparation method who is used for the oil deposit deep part fluid diversion

Technical field:

The present invention relates to a kind of preparation method of frozen glue dispersion, prepared frozen glue dispersion is used for the oil deposit deep part fluid diversion, thereby improves oil recovery factor.

Technical background:

The deep fluid diversion agent of present gel-type both domestic and external mainly comprises following a few class: body frozen glue (Bulk Gel), colloidal dispersion frozen glue (Colloidal Dispersion Gel, be called for short CDG), hydroexpanding body (Preformed Particle Gel) and little frozen glue (Microgel).The basal component of body frozen glue and colloidal dispersion frozen glue comprises polymkeric substance, linking agent and other auxiliary agents.Normally used implementing process is: polymkeric substance and linking agent are injected the stratum, and closing well is waited and is coagulated, and forms tamper shutoff formation pore space to reduce water phase permeability, last opening well and making production (or recovering water filling).The formation of body frozen glue is subjected to multiple factor affecting, for example the shear-stress that causes of uphole equipment and immediate vicinity of wellbore seepage flow causes polymer degradation, the various physicochemical property (as temperature, pH value, salinity etc.) on stratum around the pit shaft, polymkeric substance and linking agent are in the adsorption of immediate vicinity of wellbore, the stratum inhomogeneity, and the diluting effect that causes by diffusion etc.So gelation time, gel strength, the frozen glue of frozen glue enters the very difficult prediction of the degree of depth on stratum in the technology of injection of polymer and the underground gelation of linking agent, thereby influenced the validity of treatment process.

In order to solve the uncontrollable situation of gelation in the underground gelation technology, proposed to carry out the method for deep fluid diversion with hydroexpanding body (precrosslink frozen glue particle) and little frozen glue.Hydroexpanding body class particle is mainly by monomer, linking agent, auxiliary agent and intensity control agent (clay) etc., form the frozen glue viscoelastic body with certain water-swelling property under certain condition, operations such as drying, pulverizing, granulation, screening are made the serial solid particulate of different expansion multiples, varying strength, different-grain diameter again.Hydroexpanding body particulate 3 D stereo network structure contains a large amount of hydrophilic radicals, has good water-swelling property.This water-wet behavior makes it can significantly change its volume size under different condition, and the three-dimensional framework structure that produces by crosslinked action makes it have certain intensity simultaneously, can form obstruction in the stratum, and direction of flow is changed.Simultaneously deformation can take place in viscoelastic body after the water-swelling under external force, and this deformation is reversible, and deformation can recover to a certain extent when external force reduces.This " amoeba " characteristics that can make full use of are changed oil reservoir local pressure field, thereby realize the purpose that resident fluid turns to.But be subjected to the restriction of preparation condition, the particle diameter of hydroexpanding body class blocking agent is usually between 1～5mm, particle diameter increases to 10～100mm after the water-swelling, and most of hydroexpanding bodies pass through the stratum with fragmentation by the mode of hole, this mechanism of action can not be brought into play the effect of precrosslink particulate fully, and the hydroexpanding body particle grain size can not adapt to the requirement that the deep is injected.

In the latter stage nineties, Chauveteau etc. have proposed the shearing cross-linking theory and have prepared different little frozen glue systems (microgel) by this method, it has, and shutoff distance, selectivity are strong, insensitive to stratum physical and chemical condition (temperature, pressure, formation water salinity), the characteristics of good stability, but prepare the shearing cross-linking equipment that little frozen glue uses and be coaxial cylinders, this equipment shortcoming is to be not suitable for carrying out large-scale industrial production, liquid is volatile during the open container heating, can only be used for laboratory study.

Summary of the invention:

The object of the present invention is to provide a kind of preparation method who is used for the frozen glue dispersion of oil deposit deep part fluid diversion, making prepared frozen glue dispersion neither be subjected to gelation reaction, formation condition is uncontrollable influences, not limited by industrial scale, can enter earth formation deep, effectively change the flow direction of resident fluid, further improve water drive and/or the poly-recovery ratio of driving.

The present invention realizes that the technical scheme that its purpose is taked is to adopt pipe stream shearing cross-linking method, promptly in the process of polymkeric substance and linking agent formation frozen glue, this gelation system is applied certain shearing force, make the gelation system not form whole frozen glue and form the frozen glue dispersion, realize as follows:

(1) chooses peristaltic pump (BT-100B) as shearing device;

(2) choosing relative molecular mass is 4.0 * 10 ⁶, degree of hydrolysis is that 12% partially hydrolyzed polyacrylamide embodies polymkeric substance as gelation, selects chromium acetate Cr (Ac) ₃Be linking agent;

(3) getting mass ratio is partially hydrolyzed polyacrylamide: chromium acetate=160: 1～320: 1, stir, and be mixed with pipe stream cross-linking system;

(4) the rotating speed 10～150rpm of adjustment peristaltic pump sucks the above-mentioned pipe stream cross-linking system for preparing in the silica gel hose of peristaltic pump fast;

(5) with the two ends butt joint of flexible pipe, place 30～40 ℃ of waters bath with thermostatic control, constant speed is sheared 180～300 minutes to complete reaction.

(6) liquid in the silica gel hose is taken out, 3～5 times of volumes of thin up, 80～90 ℃ were stirred 240～360 minutes, promptly obtained the frozen glue dispersion that needs.

The present invention uses peristaltic pump as shearing device, to suck by the gelation system that partially hydrolyzed polyacrylamide and chromium acetate are formed in the peristaltic pump flexible pipe, thereby the rotating speed by adjusting peristaltic pump is to obtain the frozen glue dispersion of different shearing rate preparation different-grain diameter sizes, can be injected into oil deposit deep part, the frozen glue dispersion microparticle adsorbs in the duct, is detained, can reduce the rate of permeation in high permeability zones territory, make follow-up injection liquid turn to low permeability zone, play the effect of deep profile controlling.

Description of drawings

Fig. 1 is fluid flow schematic diagram in circular pipe.

Fig. 2 is the principle schematic of peristaltic pump.

Fig. 3 is that (30 ℃, data point is gelation time/h) to chromium acetate frozen glue gelation time equal-value map among the figure.

Fig. 4 is the rotating speed of peristaltic pump and the graph of a relation of shearing rate.

Fig. 5 is the influence curve of shearing rate to median size.

Fig. 6 is by 4000mgL ^-1HPAM+25mgL ^-1Cr (Ac) ₃The atomic force microscope photo of the frozen glue dispersion that forms.

Fig. 7 is by 8000mgL ^-1HPAM+25mgL ^-1Cr (Ac) ₃The atomic force microscope photo of the frozen glue dispersion that forms.

Embodiment

Further describe the present invention below in conjunction with drawings and Examples.

1. the feasibility analysis of pipe stream shearing cross-linking

Propose to replace in coaxial cylinders flow pattern in relative rotation with liquid mobile mode in pipe, it is mobile that the steady flow in the pipe is also become Poiseuille.Suppose that flowing is stable laminar flow, promptly the velocity of flow of each particle does not change in time in the fluid.Here (z), as shown in Figure 1, definition z axle is consistent with the axis of pipe for r, θ, and caliber is R to adopt cylindrical coordinates.

Fluid only flows along the z direction of principal axis, v ₂Be the function of particle from the radial distance r of pipe central shaft, not along r radially with along circumferential the flowing of θ.Writing:

v _z＝v _z(r) (1)

v _r＝v _θ＝0 (2)

With pipe wall contacting with fluid layer be immobilized, v is arranged during r=R ₂=0.

Laminar flow in the pipe can be considered as many flowing by the concentric column layer.Suppose the long l of pipe, radius is the cylinder layer fluid of r, and what be subjected to the pipe two ends adds pressure differential deltap p, and applied pressure is Δ p π r ²The outer layer fluid of this damaged surface equals shear-stress τ to its viscous resistance _RzMultiply by the long-pending 2 π rl of damaged surface.Both force balance types are:

2πrlτ _rz+Δpππ ²＝0

${\mathrm{\τ}}_{\mathrm{rz}}=-\frac{\mathrm{\Δpr}}{2l}$

As seen, the shear-stress τ on tube wall _RFor

${\mathrm{\τ}}_R={\mathrm{\τ}}_{\mathrm{rz},\max }=\frac{\mathrm{\ΔpR}}{2l}---\left(3\right)$

τ on the tube hub axle _Rz=0, shear-stress τ _RzIt is the linear function of r.

Newtonian fuid laminar flow in pipe is launched, can obtain the velocity distribution equation, use relational expression

$\mathrm{\γ}=\frac{{\mathrm{dv}}_z}{\mathrm{dr}}=\frac{\mathrm{\τ}}{\mathrm{\μ}}=-\frac{\mathrm{\Δpr}}{2\mathrm{l\μ}}---\left(4\right)$

Integration, and bring final condition r=R, v into _z=0, have

$v_z\left(r\right)=\frac{\mathrm{\Δp}}{4\mathrm{\μl}}(R^2-r^2)---\left(5\right)$

The mobile velocity flow profile is the quafric curve function in the pipe.And velocity slope is a shearing rate is the linear function of r.At the v of the place, axle center of pipe _zHas maximum value, shear-stress τ _Rz=0, shearing rate γ=0.And opposite at the tube wall place, v _z=0, shear-stress and shearing rate have maximum value.

Volumetric flow rate by the circle ring column from r to r+dr is

dq _v＝v _z(2πrdr) (6)

The flow in whole pipe cross section, integrable gets

$q_V={{\∫}_0^R\mathrm{dq}}_V={\∫}_0^R\left(\frac{\mathrm{\Δp}}{2\mathrm{\μl}}\right)(R^2-r^2)\mathrm{\πrdr}=\frac{\mathrm{\π}{R}^4\mathrm{\Δp}}{8\mathrm{\μl}}---\left(7\right)$

This formula is also referred to as the Hagen-Poiseuille equation.

On the r=R tube wall,

${\mathrm{\γ}}_{\max }=\frac{4q_V}{\mathrm{\π}{R}^3}---\left(8\right)$

For power-law fluid, if rheological equation cotype (2-22), then the velocity distribution equation is

$v_z=\left(\frac{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="H2008102376856E00022.png"\; state="\{\{state\}\}">n</figure-callout>}}{1+n}\right){\left(\frac{1}{2K}\right)}^{\frac{1}{n}}{\left(\frac{\mathrm{\&Delta;p}}{L}\right)}^{\frac{1}{n}}{R}^{\frac{1+n}{n}}[1-{\left(\frac{r}{R}\right)}^{\frac{1+n}{n}}]---\left(9\right)$

The volumetric flow rate equation is

$q_V=\left(\frac{\mathrm{\&pi;}{R}^{3}n}{3n+1}\right){\left(\frac{\mathrm{R\&Delta;p}}{2\mathrm{KL}}\right)}^{\frac{1}{n}}---\left(10\right)$

Average shear rate is

${\mathrm{\&gamma;}}_{\mathrm{ave}}=\frac{{\mathrm{dv}}_z}{\mathrm{dr}}=\frac{3n+1}{n}\&CenterDot;\frac{q_V}{\mathrm{\&pi;}{R}^3}---\left(11\right)$

Can know that by above analysis when fluid flowed, the shearing rate at tube hub place was zero in pipe, the rate of flow of fluid maximum, the shearing rate maximum at tube wall place, rate of flow of fluid is zero.Fluid also exists shear-stress and shearing rate when flowing in pipe, average shear rate can be tried to achieve by through type (11).If the mode with pipe flow prepares the frozen glue dispersion, then having a subject matter is that pipe center shearing rate is zero, can cause the part in the gelation system to produce whole frozen glue like this, and this kind situation produces adverse influence to the practical application meeting.Tube hub place shearing rate is zero disadvantageous effect in the pipe flow in order to eliminate, must take certain measure, pipe is wrapped on the right cylinder that diameter is 2.5cm, change has just taken place in flow pattern like this, flow pattern changes the flowing vertically that has certain angle into by vertically mobile, and it is zero influence that this flow pattern can reduce tube hub place shearing rate in the pipe flow.

The present invention uses peristaltic pump (BT-100B) as shearing device, and fluid is flowed in peristaltic pump flexible pipe (diameter is 3mm), and the shearing action that is produced by this pipe stream prepares little frozen glue dispersion.Fig. 2 is the structural representation of peristaltic pump, drives roller 101 by pump shaft 102 and rotates, and has produced the rotation engagement to flexible pipe 103 thus, and squeezing tube produces certain pressure reduction, and fluidic flows in the drive pipe.

2. frozen glue dispersion gelation system is determined

At first by the static gelation evaluation of gelation system having been obtained the gelation system of suitable preparation frozen glue dispersion system, the gelation system mainly is made up of polymkeric substance and linking agent.Oil field water-soluble polymers commonly used is partially hydrolyzed polyacrylamide (HPAM), and linking agent is the chromium ion linking agent.

Pipe stream shearing cross-linking method prepares in the technology of frozen glue dispersion has following 2 basic demands to formula system:

(1) the gelation time between 0.5～4 hour, the gelation time too short or oversize all be disadvantageous to shearing cross-linking technology, the gelation time is too short, the gelation system formed whole frozen glue with regard to gelation before all not entering shearing device; The gelation time is oversize, may cause polymer degradation, and during consumption energy consumption.

(2) the crosslinking reaction temperature is low, and the low cross-linking temperature of reaction helps mass preparation, and saves the energy.

Through screening, the gelation polymerization-filling thing that pipe stream shearing cross-linking method prepares the frozen glue dispersion is that relative molecular mass is 4.0 * 10 ⁶, degree of hydrolysis is 12% HPAM, linking agent is Cr (Ac) ₃, the static gelation equal-value map of gelation system as shown in Figure 3.Along with the increase of polymkeric substance and linking agent mass concentration, the system crosslinking time reduces gradually, and the gelation time of gelation system is 0.5～2 hour.

Embodiment 1: the preparation mass concentration is 8000mgL in the 100mL beaker ^-1HPAM and 25mgL ^-1Cr (Ac) ₃Pipe stream shearing cross-linking system, according to the requirement of shearing rate, the rotating speed of adjusting peristaltic pump is 10rpm, suck the pipe stream shearing cross-linking system for preparing in the silica gel hose fast, with the butt joint of flexible pipe two ends, place 30 ℃ of waters bath with thermostatic control, constant speed is sheared 4 hours to finishing.Liquid in the silica gel hose is taken out, dilute 3 times, 90 ℃ were stirred 4 hours, obtained the frozen glue dispersion that needs.

In like manner, the rotating speed of adjusting peristaltic pump from low to high is 30,50,80,100,150rpm, obtains corresponding frozen glue dispersion successively according to the method for embodiment 1.Measure the hydromeehanics diameter d of frozen glue dispersion with Malvern Zetasizer 3000 HSa dynamic light scatterings, measurement result as shown in Figure 4, the median size of frozen glue dispersion changes with-0.1126 power of shearing rate.

Fig. 5 is the influence curve of shearing rate to median size, and as can be seen from Figure 5, to same cross-linking system, along with the increase of shearing rate, median size diminishes.Shearing rate is big more, and it is big more at axial suffered stress that silica gel tube-in-tube stream cuts into eastern system, the easy more stressed fragmentation of crosslinked particle.

Embodiment 2: the preparation mass concentration is 4000mgL in the 100mL beaker respectively ^-1HPAM and 25mgL ^-1Cr (Ac) ₃And 8000mgL ^-1HPAM and 25mgL ^-1Cr (Ac) ₃Two kinds of pipe stream shearing cross-linking systems, according to the requirement of shearing rate, the rotating speed of adjusting peristaltic pump is that 40rpm (is 176s ^-1), the pipe stream cross-linking system for preparing is sucked in the silica gel hose respectively fast.With the butt joint of flexible pipe two ends, place 30 ℃ of waters bath with thermostatic control, constant speed is sheared 4 hours to finishing.Liquid in the silica gel hose is taken out, 3 times of thin ups, 90 ℃ were stirred 4 hours, obtained the frozen glue dispersion of two kinds of needs.With the microscopic appearance of two kinds of frozen glue dispersions of atomic force microscope mensuration, as Fig. 6, shown in Figure 7.As can be seen from Figure 6, the shape of frozen glue dispersion in solution mainly exists with column or bar form, according to statistics, and the about 1.3 μ m of the major axis of frozen glue dispersion, the about 0.6 μ m of minor axis, major-minor axis ratio is about 2: 1.In pipe stream shearing cross-linking process, polymers soln flows along certain direction, on flowing to, there is shearing action, in this process, be not enough to overcome shearing force as long as form the deformability of frozen glue, will be sheared into little frozen glue, and the polymkeric substance longshore current to crosslinked ability greater than perpendicular to the crosslinked ability that flows to, frozen glue that therefore can crosslinked generation bar column.As can see from Figure 7, there are isolated little frozen glue particle and little frozen glue agglomeration of particles body in the photo, according to statistics, the about 2.3 μ m of the major axis of little frozen glue, the about 0.8 μ m of minor axis, major-minor axis ratio is about 3: 1.Grain diameter obviously increases.The increase of polymer quality concentration causes crosslinkable polymer build-up in the system, and is crosslinked stronger, and the particle diameter under the therefore identical shearing force condition is bigger.

According to preparation method provided by the present invention, can control the size of frozen glue dispersion particle diameters by adjusting the shearing rate size.This frozen glue dispersion can be injected into oil deposit deep part, and absorption, the delay of frozen glue dispersion microparticle in the duct can reduce the rate of permeation in high permeability zones territory, makes follow-up injection liquid turn to low permeability zone, plays the effect of deep profile controlling.Have that viscosity is low, good fluidity, good stability, characteristics such as validity period is long, and to shear and the reservoir physical and chemical condition insensitive, controllable size can design frozen glue dispersion diameter at Different Strata, prevents to stop up stratum diafiltration face.Diameter hour can guarantee the needs that earth formation deep is handled, and can reduce water phase permeability greatly when big, and less to the permeability to oil influence; Enough " soft " can be expressed on the hole wall by water-oil interface when oil phase flows, and little to the oil phase resistance to flow, adhesive capacity is strong, and good stability is nontoxic, environmental friendliness.

Claims (1)

1. frozen glue dispersion preparation method who is used for the oil deposit deep part fluid diversion, adopt pipe stream shearing cross-linking method, in the process of polymkeric substance and linking agent formation frozen glue, this gelation system is applied shearing force, make the gelation system not form whole frozen glue and form the frozen glue dispersion, it is characterized in that realizing as follows:

1. choose peristaltic pump as shearing device;

2. choosing relative molecular mass is 4.0 * 10 ⁶, degree of hydrolysis be 12% partially hydrolyzed polyacrylamide as gelation body polymkeric substance, select chromium acetate Cr (Ac) ₃Be linking agent;

3. getting mass ratio is partially hydrolyzed polyacrylamide: chromium acetate=160: 1～320: 1, stir, and be mixed with pipe stream cross-linking system;

4. adjust the rotating speed 10～150rpm of peristaltic pump, the above-mentioned pipe stream cross-linking system for preparing is sucked in the silica gel hose of peristaltic pump fast;

5. with the two ends butt joint of flexible pipe, place 30～40 ℃ of waters bath with thermostatic control, constant speed is sheared 180～300 minutes to complete reaction;

6. the liquid in the silica gel hose is taken out, 3～5 times of volumes of thin up, 80～90 ℃ were stirred 240～360 minutes, promptly obtained the frozen glue dispersion that needs.

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