U.S. patent application number 13/506628 was filed with the patent office on 2012-11-15 for permeability modification and water shut off composition and process.
This patent application is currently assigned to OIL CHEM TECHNOLOGIES INC. Invention is credited to Christie Huimin Berger, Paul Daniel Berger.
Application Number | 20120285691 13/506628 |
Document ID | / |
Family ID | 47141099 |
Filed Date | 2012-11-15 |
United States Patent
Application |
20120285691 |
Kind Code |
A1 |
Berger; Paul Daniel ; et
al. |
November 15, 2012 |
Permeability modification and water shut off composition and
process
Abstract
A composition and process for reducing the permeability of a
matrix without completely blocking the matrix {is describe}. The
composition uses a nano-sized water insoluble particle as a
template to control the permeability by determining the size of the
holes formed in the matrix.
Inventors: |
Berger; Paul Daniel; (Sugar
Land, TX) ; Berger; Christie Huimin; (Sugar Land,
TX) |
Assignee: |
OIL CHEM TECHNOLOGIES INC
Sugar Land
TX
|
Family ID: |
47141099 |
Appl. No.: |
13/506628 |
Filed: |
May 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61518644 |
May 9, 2011 |
|
|
|
Current U.S.
Class: |
166/305.1 |
Current CPC
Class: |
C09K 2208/10 20130101;
C09K 8/50 20130101; C09K 8/502 20130101; C09K 8/516 20130101 |
Class at
Publication: |
166/305.1 |
International
Class: |
E21B 43/16 20060101
E21B043/16 |
Claims
1. A process for reducing the permeability of a solid matrix by
introducing into the reservoir matrix a composition composed of the
following a) a material capable of forming a impervious solid
matrix precursor, b) a water insoluble, {oil soluble} or oil
dispersible nano-sized material that can be used as template to
create pore spaces In the impervious gel, c) a water immiscible
carrier for the template, d) a material that can initiate the
controlled gellation of the tight otherwise impervious gel, e one
or more emulsifiers, and, f an aqueous carrier for the solid matrix
precursor, and, allowing the composition to harden creating small
pores within the larger channels of the matrix.
2. The process for reducing the permeability of a solid matrix
described in claim 1 where the material capable of forming a tight
impervious solid matrix is silica gel.
3. The process for reducing the permeability of a solid matrix
described in claim 1 where the water insoluble, oil soluble or oil
dispersible hydrophobic core is chosen from the group: magnesium
stearate, calcium stearate, oil soluble resins, oil soluble waxes
of different particle sizes and porous nano particles of different
sizes.
4. The process for reducing the permeability of a solid matrix
described in claim 1 where the water immiscible carrier is chosen
from the group: crude oil, mineral oil, diesel oil, hydrocarbon
solvent, vegetable oils, synthetic esters, natural fatty esters,
aromatic solvent.
5. The process for reducing the permeability of a solid matrix
described in claim 1 where material that can initiate the
controlled gelation of the tight impervious gel is chosen from the
group: various salts, inorganic acids, organic acids, esters, oil
soluble acids.
6. The process for reducing the permeability of a solid matrix
described in claim 1 where the material that can initiate the
controlled gelation of the tight otherwise impervious gel is added
along with the other components described in claim 1 into the pore
spaces of the matrix.
7. The process for reducing the permeability of a solid matrix
described in claim 1 where the material that can initiate the
controlled gellation of the tight otherwise impervious gel is added
after the other components described in claim 1 have been
introduced to the pore spaces of the matrix.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on provisional application Ser.
No. 61/518,644, filed on May 5, 2011
FIELD OF INVENTION
[0002] The present invention generally relates to compositions and
a method of reducing but not eliminating permeability in an
otherwise heterogeneously permeable matrix
BACKGROUND OF THE INVENTION
[0003] Relative permeability control is essential for all types of
water control problems in the oil field. The goal of a relative
permeability modifier (RPM) is to reduce the effective permeability
to water and increase the oil and/or gas production. This would
reduce water-handling problems and lost oil production.
Furthermore, the relative permeability modifier can increase the
effectiveness of a water flood and other Enhanced Oil Recovery
(EOR) processes.
[0004] None of the currently applied relative permeability modifier
processes or techniques have consistently performed well in field
operations.
[0005] The present invention of the permeability modifier can be
used in subterranean reservoirs to modify the permeability of the
high permeability areas. The permeability modifier can also be used
in many applications to modify the relative permeability and
improve the oil and gas recovery including but not limited to,
water shut off, drilling, fracturing, cementing, acidizing,
waterflooding, chemical enhanced oil recovery, (CEOR) polymer
flooding, CO2 flooding.
LIST OF FIGURES
[0006] FIG. 1 shows the structure of the internal phase and the
final solid matrix.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention involves the use of oil soluble or
dispersible nano-sized particles dispersed in a non-aqueous carrier
to form a template for providing permeable channels in an otherwise
impermeable solid matrix. The permeable solid matrix can be used
for water shut off or permeability modification that can reduce the
water channeling through fractures, vugs, or reduce the bottom
water drive without risk of sealing off the oil bearing pore spaces
in a reservoir. The rate of formation of the permeable gel and the
permeability can be controlled based on the degree of the shut off
required and the degree of penetration into the reservoir.
Propagation of a liquid or gas through an enclosed area such as an
oilfield reservoir to selectively control the permeability of the
area can be controlled. The present invention also includes the use
of oil soluble resin or sized CaCO3, NaCl as templates to enable
the oil or gas flow after the otherwise impermeable matrix id
formed.
DETAIL DESCRIPTION OF THE INVENTION
[0008] The composition of the present invention contains: [0009] a)
a material capable of forming a tight impervious solid matrix
precursor, [0010] b) a water insoluble, oil soluble or oil
dispersible material that can be used as template to create pore
spaces in the impervious gel (hydrophobic core), [0011] c) a water
immiscible carrier for the template (oil), [0012] d) a material
that can initiate the controlled gellation of the otherwise tight
impervious gel (initiator), [0013] e) optionally a porous solid
material of specific size and distribution to be used as spacer to
create channels within the gel, [0014] f) one or more emulsifiers,
and, [0015] g) an aqueous carrier for the solid matrix
precursor.
[0016] The material capable of forming a tight impervious solid
matrix includes but is not limited to sodium silicate. The water
insoluble, oil soluble or dispersible material that can be used as
a hydrophobic core to create pore spaces in the impervious gel
includes but is not limited to, magnesium stearate, calcium
stearate, oil soluble resins and/or oil soluble waxes of different
particle sizes, inorganic salts and porous nanoparticles. In the
case of application to an oilfield reservoir, the size of this
material must be small enough to allow for penetration into the
reservoir without permanently blocking small channels within the
rock.
[0017] The water immiscible carrier can be any of a number of
suitable carriers including but not limited to crude oil, mineral
oil, diesel oil, hydrocarbon solvent, vegetable oils, synthetic and
natural fatty esters, and aromatic solvent. The water immiscible
carrier is used to suspend the template material and increase the
final size of the pore spaces created in the gel. The initiator can
be any material that can initiate a chemical reaction that converts
the solid matrix precursor to a tight impervious mass. These
include but are not limited to various salts, inorganic and organic
acids, esters and/or oil soluble acids. The imitator can be
included in the internal phase or can be injected separately once
all the ingredients are in place by methods known to the art.
[0018] The porous solid can be used as a spacer to create channels
within the matrix through which liquid can flow or as a medium to
contain one or more of the ingredients for slow release from the
non-aqueous to the aqueous phase. The porous solid may also serve
to introduce other non-aqueous ingredients in the final permeable
solid matrix. Porous spheres of various sizes or oil soluble solids
can also be used to control the pore size and distribution.
[0019] The one or more emulsifiers are used to emulsify or disperse
the non-aqueous phase composed of the water immiscible template,
the water immiscible carrier and the gel initiator into the aqueous
phase.
[0020] They can be any of a number of non-ionic, anionic, cationic
or amphoteric surfactants that have been found to be suited for
such a purpose.
[0021] The aqueous carrier can be any of a number of liquids
including but not limited to water, seawater, produce brine,
synthetic brine.
[0022] The time required for the solid permeable matrix to form and
the crushing strength is determine by the ratio of solid matrix
precursor to water and the amount initiator used. Using more
initiator will speed up solid matrix formation. Usually a higher
ratio of solid a matrix precursor gives I a stronger matrix.
[0023] The permeable solid matrix can be introduced into reservoirs
containing channels, erosions, fractures, bottom water, un-wanted
gas cap, coning, etc. to partially seal or to reduce the porosity
without completely blocking off flow. After the matrix has set deep
within the reservoir it can be made permeable by passing oil or
brine or water through it to wash out the oil soluble particles
dispersed within the gel and/or remove any other entrained material
such as oil. In cases where the heat within the reservoir is high
enough the oil soluble particles can be melted in situ to form
permeable pathway through the gel. If a lipophilic surfactant is
added to the aqueous solid matrix precursor before adding the
non-aqueous phase the resulting walls of the pores formed can be
rendered hydrophobic allowing oil to pass through and rejecting
water. FIG. 1 shows the structure of the matrix formed when the
internal phase containing the oil, emulsifier, hydrophobic core and
the initiator are mixed with the external solution containing the
solid precursor.
[0024] The invention allows for tunable permeability by allowing
for changes in the "holes" formed in the matrix by changing the
size of the hydrophobic core and the amount of oil and emulsifier
used.
[0025] The intent of partially blocking the fractures is to allow
subsequent injection fluid to contact the reservoir matrix more
evenly so that more oil is contacted and can be recovered from the
reservoir. The injection fluid can be water, brine, synthetic brine
or seawater and may contain other ingredients commonly included and
known to those familiar with the art to recover residual oil from
the reservoir. These ingredients include but are not limited to
surfactants, viscosifiers, corrosion inhibitors, scale inhibitors,
biocides, clay swelling inhibitors, wetting agents.
Example 1
[0026] This example demonstrates the effect of different ratios of
internal to external phase on the solidification time.
[0027] A non-aqueous internal phase is formed by adding 20 grams of
PEG 400 dioleate (emulsifier) and 10 grams of ethyl lactate (ester)
to 20 grams of crude oil as shown in Table 1. To these, 10 grams of
powdered magnesium stearate powder is added and mixed to uniformly
disperse the magnesium stearate. In separate containers various
amounts of Sodium Silicate Type N available from PQ Corporation are
added. The non-aqueous internal phase is then added, mixed and the
entire mixture allowed to solidify according to the ratios shown in
Table 2 below.
TABLE-US-00001 TABLE 1 Internal Phase Wt % Crude Oil 40 PEG 400
Dioleate 40 Ethyl Lactate 10 Magnesium Stearate 10 Total 100
TABLE-US-00002 TABLE 2 A B C D E Internal Phase, wt % 30 20 10 5
2.5 Type N Sodium Silicate, 70 80 70 95 97.5 wt % Time to Solidify,
min <5 30 120 180 300
Example 2
[0028] This example demonstrates the application of the invention
to create a uniform porosity in a fracture sand pack. This property
is desirable for application such as Water Flooding, Chemical
Enhanced Oil Recovery (CEOR), polymer flooding, and any other
application where a uniform sweep efficiency is desired or
required.
[0029] Two 1 inch diameter by 12 in long sand packs were prepared
using gravel of collected between a No. 10 and a No 60 Tyler
screen. This provided columns having large channels simulation
fractures and vugs. One column was left untreated. The second was
treated by introducing 1 pore volume of the formulation described
in Table 2 column C. After this column and its contents were allow
to stand for 2 hours at room temperature both columns were eluted
with water containing 0.05% methylene blue. The rate of elution and
the time for initial appearance of the blue dye at the outlet of
the column for each were recorded as well as the appearance of the
material propagating through the column. These observations and
measurements are reported in Table 3.
TABLE-US-00003 TABLE 3 Untreated Column Treated Column Time for
first drops to elute <30 seconds 3.5 minutes Flow rate, ml/min
6.4 1.2 Initial time for elution of dye 45 seconds 52 minutes
Appearance Channeling Plug Flow
[0030] Further embodiments and alternative embodiments of various
aspects of the present invention may be apparent to those skilled
in the art in view of this description. Accordingly, this
description is to be construed as illustrative only and is for the
purpose of teaching those skilled in the art the general manner of
carrying out the invention. It is to be understood that the forms
of the invention shown and described herein are to be taken as the
presently preferred embodiment. Elements and materials may be
substituted for those illustrated and described herein, parts and
processes may be reversed, and certain features of the invention
may be utilized independently, as would be apparent to those
skilled in the art after having benefited by this description of
the invention. Changes may be made in the elements described herein
without departing from the spirit and scope of the invention as
described in the flowing claims. In addition, it is to be
understood that features described herein independently may, in
certain embodiments, be combined.
[0031] While the invention has been described in connection with a
preferred embodiment, it is not intended to limit the scope of the
invention to the particular form set forth, but on the contrary, it
is intended to cover such alternatives, modifications, and
equivalents as may be included within the spirit and scope of the
invention as defined by the appended claims.
* * * * *