SU721523A1 - Gas-spout suppressing method - Google Patents

Description

The invention relates to the depth of the open gas fountains. There is a known method of suppressing a fountain with blows IJ. The method requires large capital expenditures, a significant amount of preparatory work. There is also a known method of plugging a gas fountain by pumping water into the wellbore and then filling the wellbore with the desired washing liquid 2J. The disadvantage of this method is the need for high flow rates of pumping back fountains with high flow rates, in large volumes and insufficient efficiency of the fountain jamming. The aim of the invention is to increase the efficiency of gas killing photolane. The fasting goal is achieved by the fact that, with a glass of water and flushing life, the sequence and the second portion of the hydrate formation inhibitor, the hydrate formation and the second portion of the hydrate inhibitor, are pumped in the volume of 5–50 m, and the template is filled with a perforation layer (5–50 m); temperatures - 5-70 C. The proposed method is based on the property of certain gases and light-volatile liquids to form crystalline hydrates under certain thermodynamic conditions, and, most actively, crystalline hydrates are formed on the surface separation of solid, liquid and gaseous phases. Natural gas, consisting mainly of methane, is itself a good hydrating agent. However, coming from a productive formation with a relatively high temperature, it is often able to form hydrates at. the interaction with the transported out by the formation water or with the water from the surface of the spouting into the trunk. In some cases, the hydrates all teki formed np stoichlh

wells. OnvsaKo, due to the impregnation of the walls of the reservoir due to the heat transferred by the gas flow from the deep layers, after the formation of hydrates, the I.H. decomposition on the walls of the well begins immediately. As a result, the adhesion of hydrates to the wall is reduced and they are carried by the gas flow to the surface. In the proposed method, the injection of a liquid hydrate generator to the flowing well reduces the temperature of the gas flow and the temperature of the well walls due to intensive heat exchange of the cold cooled hydrate forming ice as it enters the gas flow, as a result of which the injected hydrate forming agent and natural gas will intensively form crystalline hydrates on the well wall and reduce the flow through borehole cross section.

For example, liquid propane, freon, methane and other hydrate formers can be used as a liquid hydrate forcing agent. The table shows the experimentally obtained individual data of the equilibrium conditions of some hydrate formers.

2520 41

Pressure at

O + 12 O + 8.3

Temperature, C Estimated calculations show that at a flow rate of a flowing well 1O, temperature of the walls of the well and outgoing gas ZO C, the well will be plugged with hydrates after the injection of 2Sf30 m of liquid propane with temperature -. Such an insignificant amount of liquid can be easily delivered to the flowing well. As already noted, chilled methane can be used as a liquid hydrate forming agent, which can be obtained from nearby working wells and cooled using a small mobile unit. In order to ensure the operability of the proposed method, the hydrate formation chain should be separated from the process fluids (water and the diluted washing liquid) sequentially injected into the well, a portion of the hydrate inhibitor that prevents the channel from connecting the fountain well with ground-based processing equipment to suppress the fountain. The proposed method is carried out as follows. Water is pumped into the flowing well. Depending on the specific situation, water is pumped through either the drill pipe or through a specially drilled inclined well. In the first case, the volume of injected water is 5-1 O m. In the second case, this volume of water is produced by fracturing in order to carry out the flow of the wells and the inclined well to kill the fountain. Therefore, in the latter case, the volume of injected water can be up to 5O m. Injection of this portion of water into the well is necessary. To remove gas from the channel connecting the injection equipment with the gas flow. This prrdotvrashagg possible hydrate formation in the specified channel and provides the second successful conduction of operations for killing the fountain. In addition, this volume of water provides a good interface between successively injected fluids, which prevents gas from passing to the coolant hydrate-forming agent. Then, the buffer volume of the hydrate-forming inhibitor is pumped into the flowing well to prevent hydrate formation at the bottom of the water-cooled hydrate-forming agent. The Fx route through the connecting channel, a hydrate inhibitor, for example, methanol or a calcium chloride solution, displaces water from there and absorbs moisture from the channel walls, adding to the probability of a Zakup (.1 channel of hydrant channel. The volume of the inhibitor is hydrated) the flow well depends mainly on the type of the channel connecting the equipment to the flow behind and also, like when pumping the first portion of water, is 5-50 m. After the hydrate-forming inhibitor is injected, the cooled to the flow rate Gas-hydrate forming gas -5-100С. As follows from the table of equilibrium conditions, some of the hydrate-formers selected temperature range ensures the formation of hydrates in the wellbore font well.1 It is not advisable to cool the hydrate-forming fluid below, as this can cause overcooling and blockage of the connecting channel by the inhibitor hydrant. The upper limit of the cooling of the hydrating agent was determined from the conditions of use of freon-11 bodies as hydrate-forming substances and, as an inhibitor, atoobrazovani - chloride cal chi. It is impractical to raise the temperature of the hydrate- builder above –5 ° C since it is necessary to have a supply of cold for cooling the well bore and gas flow. The volume of hydrated hydrate forming gas that needs to be pumped into the flowing well for complete blockage of the well bore in a certain interval depends on the type of hydrating agent, temperature condition of the flowing well, production rate, reservoir pressure gas and other factors and can be determined using simple calculations, similar to the calculations performed in the example below. By entering the spouting well, the cooled hydrate former will simultaneously participate in three processes: the formation of gas hydrates due to the interaction of the cooled hydrate-forming agent with dropping moisture on the walls of the well and in the flowing gas; cooling the gas stream and the walls of the well; evaporating the cooled hydrate-forming agent due to its entry into the high-velocity gas flow (i.e., into the low static pressure region) and due to this, the temperature of the hydrated and flow walls of the well may be lowered (i.e., creation of favorable conditions for the formation of gas hydrates in the wellbore) ). If cooled methane is used, instead of the process of evaporation of the hydrating agent, there will be a process of expanding the cooled methane and cooling it according to the Joule-Thomson law. After cessation of the spouting, a portion of the inhibitor of the hydrophobic injection and pumping fluid is pumped into the well and the diluted washing fluid, and the usual work is carried out to eliminate the consequences of the emergency gushing. A second portion of the hydrate formation inhibitor is pumped to separate the coolant hydrate and the thickened whey fluid. For a more effective separation of the hydrating agent and the enhanced washing liquid, the volume of the hydrate inhibitor, and in the first case, takes as 5-5 MB depending on the type of the dimensions of the connecting channel. It should be noted once again that in case of deviation from the recommended injection volumes of the hydrate formation inhibitor, there will be a decrease in the effectiveness of the proposed method. Thus, if the upper limit (50 m) of the injection volume is exceeded, the costs of implementing the method unnecessarily increase, and when inhibitor is pumped in a volume of less than 5 m, the cooled hydrate-forming agent and water or the diluted flushing liquid may occur, resulting in blockage of the connecting channel. For illustration, an example is given below of the calculation of the technological parameters of the proposed method, used when a gas fountain is peeled off with a relatively low flow rate (1 O m / day). Example. The well gushes forth with gas flow rate Yu, diameter of the wellbore 2OO mm, temperature of the well walls +2 0 С, gas temperature + 30 ° С. The killing of the fountain is made through an inclined borehole, which flows into the spout of a flowing well at a depth of 1OOO m. The pressure of the trunk and gushing well on the lip 1OOO m -15O at. The sweetener is water (1 g / sy). According to the invention, water is pumped into an inclined well and the formation fracture is performed in the meeting zone of the wells. At this operation I spend 5-5O m of water. After pumping the indicated volume of water into the inclined well, a hydrate inhibitor is injected to separate the water and hydrate former. A passage through the connecting channel, a hydrate-forming inhibitor, for example, methanol or a calcium chloride solution, absorbs moisture from the channel walls, further reducing the likelihood of channel blockage with hydrates. The volume of hydrate formation inhibitor is 5-50 m depending on the volume of the connecting channel.

After the first portion of the inhibitor, an o.cooled gas-hydrating agent is injected into the well, which, when it enters the spouting well, creates thermodynamic conditions in it that are favorable for the formation and intensive growth of crystal hydrates on the well’s stacks, which entails a decrease in the wellbore section and, accordingly, reduction of well flow rate, up to the complete cessation of the flowing flow.

In this example, the process of changing the thermodynamic conditions in the wellbore of the spouting well when pumping liquid propane with a temperature for 1O min with temperature is considered in this example, and the volume of hydrate formation necessary for injection is determined

hunkers. The calculations are based on the specific thermophysical properties of gas-hydroplastic emitters.

Claims (2)

1. A method of plugging a gas fountain by pumping it into a flowing well water with the subsequent filling of the well bore with a modified industrial fluid, characterized in that, in order to increase the efficiency of the fountain killing, between the water injection and the washing liquid, a hydration forming inhibitor, a hydrate forming agent and a second portion of the hydrate formation inhibitor are pumped in series. 2. The method according to p. 1, about tl and h ayushch and with the fact that water is pumped in a volume of 5-5 O m, and the hydrate-forming agent is pumped cooled to a temperature of -5-70s. Sources of information taken into account in the examination 1. Development and exploitation of offshore oil and gas fields. Scientific and technical collection, AzNTI, vol. 8, 1966, p. 26-29. 2. Malevansky V. D. Open gas fountains and the fight against them - M., Gostoptekhizdat, 1963, p. 183-199.