EP1525373A2

EP1525373A2 - Stimulation and injection system

Info

Publication number: EP1525373A2
Application number: EP03753039A
Authority: EP
Inventors: Samuel Miller; Kenneth Cioletti
Original assignee: United Energy Corp
Current assignee: United Energy Corp
Priority date: 2002-05-15
Filing date: 2003-05-15
Publication date: 2005-04-27
Also published as: US20070056738A1; EP1525373A4; CA2485991A1; MXPA04011351A; WO2003098104A3; WO2003098104A2; CN1668828A; AU2003247367A8; AU2003247367A1

Abstract

An apparatus (10) for introducing a vapor-containing stream into underground geological formations, pumps, conduits or tanks comprising; at least one vaporcontaining stream generator (16,32) having a liquid hydrogen peroxide fuel introduction zone, a catalyst zone and a zone for creating a backpressure of a vapor-containing stream formed by the generator; a conduit for introducing the liquid hydrogen peroxide fuel with said liquid hydrogen peroxide having a concentration of from 7095 weight percent into the vapor-containing stream generator (16,32); means (22) for directing the vapor-containing stream into the formation, pump, conduit or tank and means (35,38) for introducing a fluid into the formations, pumps, conduits or tanks.

Description

STIMULATION AND INJECTION SYSTEM

FIELD OF THE INVENTION

The invention relates to a system for injection of a vapor-containing stream and chemicals into underground formations, pumps, conduits or tanks. BACKGROUND OF THE INVENTION

Previous technologies have attempted to recover oil by injecting hydrogen peroxide into the formation and allowing uncontrolled decomposition and heating. This often resulted in down hole fires and damage to equipment.

One improvement to the direct injection of hydrogen peroxide was made by utilizing an in line vertical steam generator that could be used to cap the well head. The decomposition of hydrogen peroxide and silver mesh generated steam and oxygen, which were directly injected into the formation. Problems with this system occurred due to an inability to precisely control temperature and pressure, which resulted in damage to formations and well heads. BRIEF SUMMARY OF THE INVENTION

This invention is an improvement over the prior art. It utilizes a configuration which can allow generated vapor-containing stream to bypass the well and be released to the atmosphere. An injection system for injection of water is included to moderate the temperature at the injection site or in the injected sites. The strength (%) of the hydrogen peroxide solution can be used to control or vary pressure and heat. Increased efficiency is obtained by pre-heating the catalyst screen and using, for example, a silver screen coated with samarium oxide. The system also allows injection of treatment chemicals along with the vapor-containing stream.

The system has many applications and capabilities, due to its unique creation of a heated vapor-containing stream at various temperatures and pressure, it becomes an ideal injection system for paraffin problems in heavy crude and gas depleted formations as well as in pumps, conduits or tanks which contain or have contained heavy crude, hydrocarbons and gas. The vapor-containing stream generator may have a preheater some electric and some chemical and is capable of decomposing various percentages of H₂O₂. It has variable pressure injection pump, as well as a throttle valve to start or stop as needed. It can be operated on automatic by presetting an operating temperature and sensing the controlled temperature at various locations on the well and the injection equipment. It has two heat exchangers one for H₂O and one for various chemicals including KH30 or other compositions to soften or liquefy paraffins. The heat exchangers are temperature controlled at various temperatures for specific need of certain chemicals. They are also used at variable pressures controlled by the injection pumps and there drive units.

The systems pumps may be driven by 12 volts DC, 120 volts AC, direct drive gas engines and hydrostatic drives. If any of the systems fail there is a back up pump with a different drive. The system is fail-safe and cannot be operated until the gas generator has reached temperatures 350°F and above. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows one embodiment of the system as a schematic. DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a system utilizing at least one vapor- containing stream generator to produce and inject a vapor-containing stream which can comprise steam, heated water, heated gas, and/or chemicals into underground formations, pumps, conduits or tanks. The system uses a vapor-containing stream drive with variable pressure and temperature, a steam drive with variable pressure and temperature, and chemical injection at variable pressures and temperature, which allows custom tailored cyclic drives.

The injection system has many applications due to the ability to inject heated vapor-containing streams at various temperatures and pressures. The injection system is ideal for solving paraffin problems as well as a heavy crude and gas depleted formations as well as in pumps, conduits or tanks. In addition the system is environmentally clean and easy to operate.

The pumps and vapor-containing stream generator and generator are present in a single location, e.g., a truck. Thus, the system may be completely mobile.

Each pump has a drive unit and each is capable of injecting various chemicals and/or water or steam into the underground formations. Some of the pumps operate at high pressure and some operate at low pressure.

The system generates heat from at least one hydrogen peroxide fueled vapor- containing stream generator. The temperatures created are from ambient up to 1,300°F (704 °C) and the pressures are from zero to 2,500 psi. The generator can have a series of pre-heaters, some electric and some chemical, and is capable of decomposing various percentages of H O₂. The vapor-containing stream generators have a variable pressure injection pump for injection of the H₂O₂, as well as a throttle valve to start or stop as needed.

The generators can be operated on automatic by presetting an operating temperature and sensing the controlled temperature at various locations on the well, such as with temperature sensors clamped to the well seals, and on the injection equipment. The generators have heat exchangers, one for water to regulate temperature and one for various chemicals, such as KH30. The heat exchangers are temperature controlled at various temperatures and are selected based on the chemicals used. They are also used at variable pressures controlled by the injection pumps and their drive units.

The pumps may be driven by any suitable means such as 12 volts DC, 120 volts AC, direct drive gas engines and hydrostatic drivers. The pumps have automated drive units. Preferably there is a backup pump with a different drive in case any of the pumps fail.

The system also has monitors for formation back pressure. The system is fail-safe and cannot be operated until the gas generator has reached temperatures of 350°F and above. The system provides short injection times and is capable of producing large amounts of ceded gas.

Generally the system is hooked up to a well and the water and/or chemicals are injected into the well at various intervals. For example, heated gas is injected into the well for about 1 minute to about 60 minutes. The temperature of the heated gas generally ranges from 15°C to about 700°C at the well head and at a pressure of about 1 psi to about 3000 psi above the backpressure. Then a chemical such as KH30 is injected into the well followed by additional heated gas at an increased backpressure of about 1 psi to about 3000 psi above the well backpressure. The process may be repeated and varied as needed to clean the well.

The apparatus for introducing a vapor-containing stream into underground geological formations, pumps, conduits or tanks of this invention comprises: at least one vapor-containing stream generator having a liquid hydrogen peroxide fuel introduction zone, a catalyst zone and a zone for creating a backpressure of a vapor-containing stream formed by the generator; a conduit for introducing the liquid hydrogen peroxide fuel with said liquid hydrogen peroxide having a concentration of from 70-98 weight percent into the vapor-containing stream generator; means for directing the vapor-containing stream into the formation, pump, conduit or tank and means for introducing a fluid into the formations, pumps, conduits or tanks.

The apparatus can further comprise means for introducing a water-containing fluid into the formation, pump, conduit or tank downstream of the means for directing the vapor-containing stream into the formation, pump, conduit or tank. The vapor-containing stream is at a temperature of at least about 212° F. The apparatus can further include means for flushing the conduit as well as the formation, conduit, pipe or tank prior to introducing the vapor-containing stream into the formation, conduit, pipe or tank as well as valve-means in the conduit for venting to atmosphere said vapor-containing stream. The apparatus can also have a second valve-means for cooperating with the valve-means to effect flow of the vapor-containing stream into the conduit, pipe, conduit or tank with concomitant discontinuance of venting flow. The present invention also is directed to a process for introducing a vapor- containing stream into a geological formation, a pump, a conduit or a tank for effecting stimulation of flow of material in the formation, pump, conduit or tank wherein the process comprises:

(a) introducing hydrogen peroxide having a concentration of from 70 to 98% into at least one vapor-containing stream generator;

(b) passing the hydrogen peroxide into a catalyst zone of at least one generator to generate a vapor-containing stream;

(c) introducing the vapor-containing stream from at least one generator and a fluid to enhance the flow of material from said formation, pump, conduit or tank; and

(d) enhancing the flow of material in the formation, pump, conduit or tank. In the present process, the vapor-containing stream is at a temperature of at least about 212° F.

Description of Figures

The diagram illustrated in figure 1 depicts a vapor-containing steam generator assembly that employs two thermal pressure generators (16+32) that can be used simultaneously with each other or individually to each other. The thermal pressure generators (TPG) are comprised of a catalyst metered injection plate (12), a catalyst (not labeled), anti-channel baffles (14), a catalyst retainer plate (15), and a venturi .067 - .500 (17). Each thermal pressure generator will be equipped with an H2O2 heating band (11) and a catalyst heating band (13) to be used before the initial activation of the generators, this start up temperature will ensure H2O2 decomposition when introduced into each catalyst bed of the two generators. These two generators are connected to the TPG tree assembly (19) by flow directors (18) which consists of heavy wall stainless steel. Between both generators are high temperature/high pressure check valves (21), which protect the generators from over pressurization and catalyst contamination. Upon thermal pressure generator activation the vapor-containing stream is released to atmosphere through a normally open electric/pneumatic activated (EPA) vent valve (33), until the desired temperatures and system's ok are met. At that moment the normally open EPA vent valve then closes in harmony with the opening of the normally closed EPA main injection valve (20) to introduce the vapor-containing stream to another high temperature/high pressure check valve (21). This check valve initially prevents the TPG tree assembly from over pressurization and catalyst contamination. Finally, the vapor-containing stream exists through the quick connect coupling (22).

There are three injection lines located on the TPG assembly tree, one between both generators, which is incorrectly labeled as (38), this injection line is a secondary H2O injection line. The next being the H2O primary injection line (35), which is located right below the EPA vent valve these two injection lines provide temperature control and saturation content within the vapor-containing stream. Both injection lines can be actuated simultaneously or independent of each other The final injection line can be found below the EPA main injection valve, this line delivers KH30 downstream in an atomized flow (38).

The vapor-containing stream generator assembly is not only comprised of the TPG tree assembly but also a fluid, air and fuel supply system. These systems begin with the fuel supply, consisting of a H2O2 tank reservoir (3), which would contain hydrogen peroxide that would be filled and properly vented through the reservoir's fill and vent (2). Under the control of the EPA H2O2 supply valve (4), the EPA H202 injection valve (8), and the EPA H2O2 injection valve (30) the fuel can be directed to either or both thermal pressure generators by means of the H2O2 pump (7). The fuel supply is then coupled right before the TPG units by check valves (9+31) to protect the fuel supply system, hi the case of H2O2 pump failure, pump cavitation or any system failure, there is an EPA bypass valve (5) and a safety relief (6) surrounding the H2O2 pump.

The fluid systems seen in figure 1 consist of an H2O delivery and a KH30 delivery. The KH30 fluid system will be explained lastly after the air system since the H2O and air system somewhat coincide with one another. The H2O supply depicted in figure 1 is comprised of a H2O tank reservoir (50) with a H2O tank fill/vent (51). The system routes in multiple paths to provide a failsafe for essentially any mechanical failure in the H2O delivery to the TPG tree assembly. The first path is controlled by the EPA primary H2O injection supply valve (49), which opens to introduce H2O to two independent H2O injection lines under the control of two different EPA H2O injection valves (37+24), both lines are coupled with a check valve (36+23) before the injection line to provide no back flow. This H20 injection path is powered by the primary H2O pump (46), and outfitted with a safety relief (47) surrounding the pump. Both H2O injection lines can be actuated simultaneously or independently.

The secondary path is bifold because its serves two purposes; one of which is a secondary pump back up and the other purpose deals with post TPG activation in which I like to call the "cleaning" cycle or the flush system. The secondary backup system is powered by an H2O pump (48) which delivers H2O under the control of the EPA H2O injection secondary pump backup valve (25) to the two independent EPA H2O injection valves (again 24+37) in case of H2O primary pump (again 46) failure. This provides a failsafe for the temperature control and saturation content. The flush system is under the controls of the EPA H2O flush injection valve (26), the EPA bypass valve (again 5), and the EPA H2O2 injection valves (again 8+30). It is primarily powered by the secondary H2O pump (again 48), but in the case of the secondary H2O pump failing the flush system can be rerouted. This alternate route is under the control of the EPA primary H2O injection supply valve (again 49), the EPA H2O injection secondary pump backup valve (again 25), the EPA H2O flush injection valve (again 26), the EPA bypass valve (again 5), and the EPA H2O2 injection valves (again 8+30). The secondary routing is powered by the primary H2O pump (again 46). The flush system can only be actuated after post activation of the thermal pressure generators. This flush system initially begins with the deactivation of the H2O2 pump (again 7), the closing of EPA H2O2 supply valve (again 4), and then the disconnection of H2O2 fuel delivery lines at the primary coupler directly before both thermal pressure generators. After disconnection the injection of H2O "cleanses" the H2O2 fuel delivery line of any excess H2O2 left within the line. The flush system also coincides with the air system, which is the second part of the flush system. It is comprised of an air purge supply (29), and under the control of the EPA air purge injection valve (28), the EPA bypass valve (again 5), and the EPA H2O2 injection valves (again8+30), which when opened forces air through the previously flushed H2O2 fuel delivery lines. The purpose is to then force outward and dry any H2O left in the H2O2 delivery line, making it safe and ready for transport. The air system also has its own safety feature involving an inline air purge check valve (27) to ensure nothing overcomes the air purge supply or valve.

The final fluid system, which will conclude the overview of figure 1, is the chemical injection system. This system is comprised of a KH30 tank reservoir (44), which is constructed with a fill/vent (45). The system is under control of the KH30 EPA injection supply valve (43) and the KH30 EPA injection valve (40), the system itself is powered by the KH30 injection pump (42). It is located between the two valves. This pump is also surrounded by a safety relief (41) to ensure the pump itself will be in a looped cycle when the KH30 injection supply valve (again 43) is open and the KH30 EPA injection valve (again 40) is closed. It also has a check valve between the KH30 EPA injection valve (again 40) and the KH30 injection line (again 38) to provide assurance that nothing will overcome the KH30 fluid system.

The safety relief found on pumps 7, 42 and 46 are there because the pumps are constantly running upon there primary valve actuation to provide a constant loop system for pumps when primary supply valves are open and injection valves are closed.

While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the Invention, hi addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto.

Claims

What is claimed:

1. An apparatus for introducing a vapor-containing stream into underground geological formations, pumps, conduits or tanks comprising; at least one vapor-containing stream generator having a liquid hydrogen peroxide fuel introduction zone, a catalyst zone and a zone for creating a backpressure of a vapor-containing stream formed by the generator; a conduit for introducing the liquid hydrogen peroxide fuel with said liquid hydrogen peroxide having a concentration of from 70-95 weight percent into the vapor-containing stream generator; means for directing the vapor-containing stream into the formation, pump, conduit or tank and means for introducing a fluid into the formations, pumps, conduits or tanks.

2. The apparatus according to Claim 1, further comprising means for introducing a water-containing fluid into the formation, pump, conduit or tank downstream of the means for directing the vapor-containing stream into the formation, pump, conduit or tank.

3. The apparatus of Claim 1, wherein the vapor-containing stream is at a temperature of at least about 212° F.

4. The apparatus of Claim 1, further including means for flushing the conduit as well as the formation, conduit, pipe or tank prior to introducing the vapor- containing stream into the formation, conduit, pipe or tank.

5. The apparatus according to Claim 1, further comprising valve-means in the conduit for venting to atmosphere said vapor-containing stream.

6. The apparatus according to Claim 5, further comprising a second valve-means for cooperating with the valve-means to effect flow of the vapor- containing stream into the conduit, pipe, conduit or tank with concomitant discontinuance of venting flow.

7. A process for introducing a vapor-containing stream into a geological formation, a pump, a conduit or a tank for effecting stimulation of flow of material in the formation, pump, conduit or tank comprising:

(a) introducing hydrogen peroxide having a concentration of from 70 to 95% into at least one vapor-containing stream generator;

(b) passing the hydrogen peroxide into a catalyst zone of at least one generator containing a catalyst adapted to decompose the peroxide to generate a vapor-containing stream;

(d) enhancing the flow of material in the formation, pump, conduit or tank.

8. The process of Claim 7, wherein the vapor-containing stream is at a temperature of at least about 212° F.