<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-02-06</periodOfReport>

    <issuer>
        <issuerCik>0000821189</issuerCik>
        <issuerName>EOG RESOURCES INC</issuerName>
        <issuerTradingSymbol>EOG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001761421</rptOwnerCik>
            <rptOwnerName>Boedeker Kenneth W.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1111 BAGBY, SKY LOBBY 2</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP Exploration and Production</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5193</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20157</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Reporting Person received an award of 10,387 Performance Units on September 26, 2019 (&quot;2019 Award&quot;). The performance metric applicable to this award is the total shareholder return (&quot;TSR&quot;) of the Issuer over a three-year performance period (January 2020 through December 2022) relative to the TSR of each of the Issuer's nine (9) designated peer companies. Pursuant to the terms of the award agreement, between 0% and 200% of the award could be earned based on the Issuer's TSR rank for such performance period. The Issuer's TSR rank and performance multiple (as certified by the Issuer's Compensation and Human Resources Committee on February 6, 2023) was 7 and 50%, respectively. Accordingly, 5,194 Performance Units have been deducted from the 2019 Award and 5,193 aggregate Performance Units will &quot;cliff&quot; vest on February 28, 2023.  The shares of the Issuer's common stock represented by such Performance Units will be distributed to the Reporting Person following such vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Vicky Strom, attorney-in-fact for Kenneth W. Boedeker</signatureName>
        <signatureDate>2023-02-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
