Kureha Corporation

Hikaru Saijo

Masayuki Okura

Hiroyuki Sato

Takeo Takahashi

Fuminori Kobayashi

Takuma Kobayashi

Katsumi Yoshida

Takahiro Watanabe

Mizuki Saito

Hiroaki Yoshida

A downhole tool that has a high initial compressive strength, can maintain compressive strength for a certain period of time, and is rapidly degradable after use. The downhole tool is formed from a degradable resin composition containing a polyamide resin and a carboxylic acid anhydride, and the carboxylic acid anhydride is a compound satisfying the following melting point condition:melting point of polyamide resin&#x2264;5% weight reduction temperature of carboxylic acid anhydride.

Downhole tool

A rubber composition for downhole tools having excellent degradability and storability is provided. The rubber composition for downhole tools includes degradable rubber, a degradation accelerator, and a degradation inhibitor. The degradation accelerator is at least one type of the compound represented by Formula (I) or Formula (II) below. The degradation inhibitor is at least one type selected from the group consisting of carbodiimide compounds, oxazoline compounds, oxazine compounds, and epoxy compounds. The content of the degradation accelerator is from 0.1 to 20 parts by mass relative to 100 parts by mass of the degradable rubber. The content of the degradation inhibitor is from 0.1 to 3 parts by mass relative to 100 parts by mass of the degradable rubber.

Rubber composition for downhole tools and member for downhole tools

A composition for downhill tool, a degradable rubber member for a downhole tool, a downhole tool, and a method for well drilling are provided which contribute to cost reduction and process shortening and can contribute to improvement of production efficiency. A degradable rubber and a degradation accelerator comprising at least one type of compounds represented by a general formula (I) below at the ratio from 0.1 to 20 parts by mass to 100 parts by mass of the degradable rubber, containing the composition for a down hole tool, i.e. degradable rubber member for a down hole tool, and a method for well drilling using them. (In Formula (I), Rand Rare each individually alkyl groups having from 1 to 5 carbons or phenyl groups).

Composition, composition for downhole tools, degradable rubber member for downhole, downhole tool, and method for well drilling

A composition for downhill tool, a degradable rubber member for downhole tool, a downhole tool, and a well drilling method are provided which contribute to cost reduction and process shortening and can contribute to improvement of production efficiency. The composition comprises a degradable rubber and a decomposition accelerator and comprises 0.1 to 20 parts by mass of at least one type of compound represented by the following general formula (I) per 100 parts by mass of the degradable rubber, the composition for a down hole tool includes the same, the degradable rubber member for down hole tool includes the same, and a well drilling method using the same. (In formula (I), R is an alkyl group having from 2 to 6 carbons).

A downhole tool member for hydrocarbon resource recovery, comprising a shaped body of a polyglycolic acid resin having a weight average molecular weight of at least 70,000, having an effective thickness which is &#xbd; or more of a critical thickness of surface decomposition, and exhibiting a thickness reduction rate in water which is constant with respect to time. As a result, it has become possible to more accurately design the strength and time up to the collapse of the downhole tool member which forms the whole or a part of a downhole tool for developing or repairing downholes for recovery of hydrocarbon resources, such as oil and gas.

Downhole tool member for hydrocarbon resource recovery

Member for hydrocarbon resource collection downhole tool

Described are a molded product having an effective thickness of 1 mm or more, the molded product being formed from an aliphatic polyester resin composition containing from 1 to 30 parts by mass of a carboxylic acid anhydride and preferably further containing from 1 to 50 parts by mass of at least one type of a short fiber reinforcing material, a thermoplastic elastomer, or an acrylic rubber core-shell polymer per 100 parts by mass of an aliphatic polyester resin containing not less than 50 mass % of a polyglycolic acid resin, the effective thickness being 1 mm or more; a downhole tool for hydrocarbon resource recovery formed from the molded product having an effective thickness of 1 mm or more; an aliphatic polyester resin composition for the downhole tool member for hydrocarbon resource recovery; and a well drilling method.

Molded product having effective thickness of 1 mm or more and containing aliphatic polyester resin, and downhole tool member for hydrocarbon resource recovery

A fiber formed from a resin that degrades in treatment fluid for hydrocarbon resource recovery, an oligomer component content of a resin forming an outer surface of the fiber being not greater than 1 mass %, and a birefringence of the fiber being not less than 0.02; a method for manufacturing a degradable fiber for use in well treatment fluid, the oligomer component content of a resin that forms an outer surface of an undrawn yarn obtained in a spinning step being not greater than 1 mass %, and a birefringence of a drawn yarn before heat treatment in a drawing step being not less than 0.02; and a well treatment method using the well treatment fluid containing the degradable fiber for use in well treatment fluid and a proppant.

Degradable fiber for use in well treatment fluid, method for manufacturing same, and well treatment method

A downhole tool member for hydrocarbon resource recovery, comprising a shaped body of a polyglycolic acid resin blended with an inorganic or organic short fiber reinforcement material, and having thickness reduction rate characteristics when held in water at 120&#xb0; C., inclusive of: an initial thickness reduction rate (as an average for a holding period for 4 hours) which is at most 0.8 times that of a shaped body of the polyglycolic acid resin alone, and has a terminal thickness reduction rate (after the thickness decreases to 50% or less of an initial thickness) which is larger than 1.5 times the initial thickness reduction rate.

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Tokyo, Japan

Hikaru Saijo