BACKGROUND

Current devices and methods for collecting groundwater can be cumbersome to use and may underestimate or overestimate the dissolved gas concentrations. For example, one technique uses a bag that is attachable to a faucet or other groundwater source. When the bag is used to collect groundwater with a relatively high concentration of dissolved gases (i.e., two phase groundwater systems), bubbles of gas and water are simultaneously collected. However, the bag does not provide a vent for purging or degassing the collected groundwater.

Other collection devices include serum vials and volatile organic analysis (VOA) vials. The serum vials are difficult to purge in the field, and the VOA vails provide poor sample storage.

Thus, there is a need for a simplified and effective collection device and method for collecting groundwater or other fluids in the field.

BRIEF SUMMARY

Various implementations include a collection device that includes a hollow body, a first septa, a second septa, and a needle. The hollow body has a first end and a second end. The first end defines a first opening, and the second end defines a second opening. The body defines a reservoir between the first and second ends. The first septa is disposed within the first opening. The second septa is disposed within the second opening. The needle is removably disposed through the first septa. The needle has a first end disposed outside of the septa and the reservoir and a second end disposed in the reservoir and outside of the septa. The body includes a rigid, transparent, and gas impermeable material. And, a fluid comprising a gas state and a liquid state is collectable in the reservoir through the first needle.

In some implementations, the first end and the second end are opposite and spaced apart from each other.

In some implementations, the first end defines a first neck that defines the first opening and the second end defines a second neck that defines the second opening. The first neck and the second neck have a perimeter that is less than a perimeter of the reservoir.

In some implementations, the needle is a first needle, and the device further includes a second needle. The second needle is removably disposed through the second septa. The second needle has a first end disposed outside of the second septa and the reservoir and a second end disposed in the reservoir and outside of the second septa.

In some implementations, the body material includes glass.

In some implementations, the septa comprises rubber.

In some implementations, the device is a groundwater collection device.

Various implementation include a method of fluid collection comprising: (1) providing a collection device, the collection device comprising a body having a first end and a second end, the first end defining a first opening, the second end defining a second opening, the body defining a reservoir, a first septa being sealingly disposed within the first opening, a second septa being sealingly disposed within the second opening, and the body comprising a rigid, transparent, and gas impermeable material; (2) penetrating a first needle through the first septa, the first needle having a first end disposed outside of the septa and the reservoir and a second end disposed in the reservoir and outside of the septa; (3) penetrating a second needle through the second septa, the second needle having a first end disposed outside of the septa and the reservoir and a second end disposed in the reservoir and outside of the septa; and (4) collecting a fluid into the reservoir of the body by introducing the fluid into fluid communication with the first end of the first needle, the fluid comprising a gas state and a liquid state.

In some implementations, the method includes introducing a back pressure fluid into the reservoir through the second needle during at least a portion of the fluid collection.

In some implementations, the method includes venting gas within the reservoir that has escaped from the collected fluid through the second needle.

In some implementations, the method includes removing the second needle from the second septa during or following fluid collection.

BRIEF DESCRIPTION OF THE DRAWINGS

The device is explained in even greater detail in the following exemplary drawings. The drawings are merely exemplary to illustrate the structure of preferred devices and certain features that may be used singularly or in combination with other features. The invention should not be limited to the

implementations shown.

FIG. 1 illustrates a cross sectional view of a collection device according to one implementation. FIG. 2 illustrates perspective views of a septa according to one implementation.

DETAILED DESCRIPTION

Various implementations include devices and methods for collecting a fluid (e.g., groundwater) and preserving the collected sample within the collection device during transportation from the field to the laboratory. The collection device includes a hollow body having first and second ends, and each end defines an opening. The collection device also includes a septa disposed within each opening and at least one needle removably disposed within each septa. Each needle has a first end disposed within a reservoir defined by the body and outside of the septa and a second end disposed outside of the reservoir and outside of the septa. In some implementations, one needle is used to fill the device with the fluid, and a second needle is used to vent gas and/or fluid from the device or apply backpressure to the fluid during collection. The body of the collection device is rigid, transparent, and impermeable to most gases (e.g., glass). In some implementations, the ends are separate and spaced apart from each other.

For example, FIG. 1 illustrates a cross sectional view of one implementation of a collection device. The collection device 100 includes a hollow, cylindrical glass body 102, a first rubber septa 112, a second rubber septa 114, a first needle 116, and a second needle 126. The hollow body has a first end 104 and a second end 106 that are opposite and spaced apart from each other and defines a reservoir, or vessel, 136 between the ends 108, 110. The first end 104 defines a first opening 108, and the second end 106 defines a second opening 110. The first septa 112 is disposed in the first opening 108, and the second septa 114 is disposed in the second opening 110. The septa 112, 114 may be removed from the openings 108, 110 and replaced as needed. The septa 112, 114 seal against the openings 108, 110 to prevent any fluid from escaping the reservoir 136.

The first needle 116 is removably disposed through the first septa 112 such that a first end 118 of the needle 116 is disposed outside of the septa 112 and the reservoir 136 and a second end 120 of the needle 116 is disposed outside of the septa 112 and within the reservoir 136. The second needle 126 is removably disposed through the second septa 114 such that a first end 128 of the needle 126 is disposed outside of the septa 114 and the reservoir 136 and a second end 130 of the needle 126 is disposed outside of the septa 114 and within the reservoir 136. Groundwater flows into the reservoir 136 through the first needle 116, and gas, groundwater, or another fluid flows through the second needle 126. For example, gas within the groundwater that reaches the reservoir 136 and needs to be vented from the sample during the early stage of the collection flows through the second needle 126 out of the reservoir 136. This property allows the reservoir 136 to be purged with fluid to achieve a representative sample collection.

Alternatively, in situations in which back pressure is needed on the sample to prevent dissolved gas from escaping, the second needle 126 delivers a back pressure fluid into the collection device 100 as the sample is being collected. Once a fluid sample is collected or the back pressure fluid is no longer necessary, the second needle 126 is removed. When collection of the sample is completed, the first needle 116 is removed. Because the septa 112, 114 are rubber and the holes created by the needles 116, 126 are small, the holes pierced by the needles 116, 126 seal back together after the needles 116, 126 are removed and do not allow any collected fluid to escape the reservoir 136. The collection device 100 may then be transported to a laboratory to allow the sample to be analyzed.

In some implementations, the first needle 116 is coupled to a syringe body, which is coupled to a conduit carrying the groundwater to be collected. The groundwater flows from the conduit into the syringe and then through the needle 116 into the reservoir 136. In other implementations, other suitable couplings may be used to couple the needle 116 to the source.

The body 102 shown in FIG. 1 includes a central portion 135 and necked portions 122, 124 at each end of the body 102 that define openings 108, 110, respectively. The diameter around the necked portions 122, 124 is less than the diameter around the central portion 135 in the implementation shown in FIG. 1.

Each septa 112, 114 includes a body portion 142 that is engaged within the respective opening 108, 110 of the body 102. Each septa 112, 114 also includes a head portion 140. The diameter of an outer radial surface of the body portion 142 is selected to seal against an inner radial surface of the opening 108, 110. For example, the diameter of the body portion 142 may be selected to be the same or slightly greater than the inner diameter of the openings 108, 110. The head portion 140 has a diameter that is greater than the diameter of the body 102 and the inner diameter of the opening 108, 110. An inner surface 144 of the head portion 140 is disposed against a portion of the body 102 defining the opening 108, 110.

However, in other implementations, the head portion of the septa may not have a diameter that is larger than the body portion of the septa, and the inner surface of the head portion of the septa may not be disposed against the body of the collection device.

The needles 116, 126 include 23 gauge hypodermic needles having a length of between 1 to 1.5 inches, depending on the depth of the septa through which the needles are being disposed. However, in other implementations, the gauge and/or length may be varied depending on the dimensions of the septa used, the fluid being collected, and the equipment being used to feed the fluid into the needles.

In the implementation shown in FIG. 1, the ends 104 and 106 of the body 102 are opposite and spaced apart from each other along a central axis A-A of the body 102. However, in other

implementations, the body may include ends that are spaced apart at an angle of less than 180°. For example, an axis extending through one end may be spaced apart from an axis extending through the other end by 90°. In addition, in the implementation shown in FIG. 1, the ends 104, 106 define necked portions 122, 124, but in other implementations, the ends may not include necked portions. Furthermore, although glass is used for the body material in the implementation shown in FIG. 1, other suitable materials that are rigid, transparent, and gas impermeable may be used instead. And, although rubber is used for the septa material in FIG. 1, other suitable materials may be used that allow the septa to seal the openings and self- seal around the needles and against itself when the needles are removed. In addition, the body 102 described above in relation to FIG. 1 is cylindrical, but other shaped bodies may be used in other implementations.

When groundwater is being collected with the collection device 100, the device 100 may need to be purged several times (e.g., 2, 3, 4, 5, or more times) before the sample is sealed within the reservoir

136. The second needle 126 allows continuous flow through the reservoir for the purging process until the sample is ready to be taken, which makes the process easier and more efficient for the collector.

In addition, the glass body of the collection device 100 shown in FIG. 1 is easy to clean, which allows the body to be reused for subsequent samples. The glass body is also transparent, which allows the collector to see if bubbles are developing in the collected fluid and vent the gas or adjust the collection process if necessary. Furthermore, the glass body prevents gases from diffusing through it over time, preserving the sample until it can be tested.

The collection device 100 according to some implementations allows for the collection of fluids at their source (e.g., collection of groundwater at the well, surface waters, ocean water, lake water), which increases the likelihood that the gases dissolved within the fluid are maintained in the sample. Furthermore, the device 100 is useful for shallow collection (e.g., wells that are less than or equal to 100 feet deep) as well as deep collection that may be necessary with oil and gas operations (e.g., wells that are over 2000 feet deep). In addition, the device 100 is useful for a variety of fluids having dissolved gases. And, the flow through design of the device 100 allows for the elimination of air bubbles during collection while still allowing for the collecting of supersaturated dissolved gases within the collected fluid. The device 100 is easy to use in the field and requires less steps for set up than known collection devices, which reduces the opportunity for collector errors and increases the likelihood of obtaining good samples.

The terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The implementation was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various implementations with various modifications as are suited to the particular use contemplated.