-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VnTemeHtlc6ILHBp7aShi5YCMWKsknu8Ff6oHfgq4Ml/AkcJU+glr9JT5NMHtz3Q
 ptQzRdlvrWFmRRtNdravRA==

<SEC-DOCUMENT>0001181830-04-000001.txt : 20040105
<SEC-HEADER>0001181830-04-000001.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105164518
ACCESSION NUMBER:		0001181830-04-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031230
FILED AS OF DATE:		20040105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			REYNOLDS D C
		CENTRAL INDEX KEY:			0001181830

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07810
		FILM NUMBER:		04505672

	MAIL ADDRESS:	
		STREET 1:		605 RICHARD ARRINGTON JR BLVD N
		CITY:			BIRMINGHAM
		STATE:			AL
		ZIP:			35203-2707

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENERGEN CORP
		CENTRAL INDEX KEY:			0000277595
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS DISTRIBUTION [4924]
		IRS NUMBER:				630757759
		STATE OF INCORPORATION:			AL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		605 RICHARD ARRINGTON JR BLVD N
		CITY:			BIRMINGHAM
		STATE:			AL
		ZIP:			35203-2707
		BUSINESS PHONE:		2053262997

	MAIL ADDRESS:	
		STREET 1:		605 RICHARD ARRINGTON JR BLVD N
		CITY:			BIRMINGHAM
		STATE:			AL
		ZIP:			35203

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALAGASCO INC
		DATE OF NAME CHANGE:	19851002
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-12-30</periodOfReport>
    <issuer>
        <issuerCik>0000277595</issuerCik>
        <issuerName>ENERGEN CORP</issuerName>
        <issuerTradingSymbol>EGN</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181830</rptOwnerCik>
            <rptOwnerName>REYNOLDS D C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>605 RICHARD ARRINGTON, JR. BLVD. NORTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BIRMINGHAM</rptOwnerCity>
            <rptOwnerState>AL</rptOwnerState>
            <rptOwnerZipCode>35203-2707</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>President of Subsidiary</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock (ESP)</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13455</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>ESP</value><footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock (Restricted)</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1030</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></o
wnershipNature></nonDerivativeHolding><nonDerivativeTransaction><securityTitle><value>Common Stock (Deferred)</value></securityTitle><transactionDate><value>2003-12-31</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>4</value></transactionShares><transactionPricePerShare><value>41.03</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>4053</value><footnoteId id="F2"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock (Jt Ten - Brokerage 
Acct.)</value></securityTitle><transactionDate><value>2003-12-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>F</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>761</value></transactionShares><transactionPricePerShare><value>41.96</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11577</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>       (Same as above)</value></securityTitle><transactionDate><value>2003-12-30</value></transactionDate><transactionCoding><transactionFormType>4</trans
actionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1750</value></transactionShares><transactionPricePerShare><value>18.25</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13327</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock (IRA)</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>104</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></na
tureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock (Wife's IRA)</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>104</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>IRA (Wife)</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13602</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1696</valu
e></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Custodian for Daughter</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2374</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Custodian for Son</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (NQ)</value></securityTitle><conversionOrExercisePrice><value>18.25</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F3"/></exerciseDate><expirationDate><value>2007-11-24</value></expirationDate><underlyingSecurity><und
erlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3566</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>3566</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeTransaction><securityTitle><value>Stock Option (Right to Buy) (ISO)</value></securityTitle><conversionOrExercisePrice><value>18.25</value></conversionOrExercisePrice><transactionDate><value>2003-12-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1750</value></transactionShares><transactionPricePerShare><footnoteId id="F5"/></transactionPricePerShar
e><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F4"/></exerciseDate><expirationDate><value>2007-11-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1750</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>14684</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (ISO)</value></securityTitle><conversionOrExercisePrice><value>27.4375</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F6"/></exerciseDate><expirationDate><value>2010-10-24</value></expirationDate><underlyingSecurity><u
nderlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>9000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>9000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (NQ)</value></securityTitle><conversionOrExercisePrice><value>27.4375</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F7"/></exerciseDate><expirationDate><value>2010-10-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</val
ue></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (NQ)</value></securityTitle><conversionOrExercisePrice><value>22.63</value></conversionOrExercisePrice><exerciseDate><value>2004-10-24</value></exerciseDate><expirationDate><value>2011-10-23</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1142</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1142</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><deri
vativeHolding><securityTitle><value>Stock Option (Right to Buy) (ISO)</value></securityTitle><conversionOrExercisePrice><value>22.63</value></conversionOrExercisePrice><exerciseDate><value>2004-10-24</value></exerciseDate><expirationDate><value>2011-10-23</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>4418</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>4418</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (NQ)</value></securityTitle><conversionOrExercisePrice><value>29.71</value></conversionOrExercisePrice><exerciseDate><value>2006-01-29</value></exerciseDate><expirationDate><v
alue>2013-01-28</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>4135</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>4135</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Stock Option (Right to Buy) (ISO)</value></securityTitle><conversionOrExercisePrice><value>29.71</value></conversionOrExercisePrice><exerciseDate><value>2006-01-29</value></exerciseDate><expirationDate><value>2013-01-28</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3365</value></underlyingSecurityShares></underlyingSecurity><postTra
nsactionAmounts><sharesOwnedFollowingTransaction><value>3365</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding></derivativeTable><footnotes><footnote id="F1">Energen Corporation Employee Savings Plan, number of shares and securities are estimates based on trustee's unit accounting.</footnote><footnote id="F2">Energen Corporation Deferred Compensation Plan, number of securities is estimated based on recordkeepers' unit accounting.  </footnote><footnote id="F3">The option becomes exercisable in three annual installments of 1,188, 1,188 and 1,190 on November 25, 1998, 1999 and 2000, respectively.</footnote><footnote id="F4">The option becomes exercisable in three equal annual installments on November 25, 1998, 1999 and 2000.</footnote><footnote id="F5">Exercise or conversion of a derivative security.</footnote><footnote id="F
6">The option becomes exercisable in three equal annual installments on October 25, 2001, 2002 and 2003.</footnote><footnote id="F7">The option becomes exercisable in three annual installments of 333, 333 and 334 on October 25, 2001, 2002 and 2003, respectively.</footnote></footnotes><remarks/><ownerSignature><signatureName>J. D. Woodruff, Attorney in Fact</signatureName><signatureDate>2004-01-05</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----