<SEC-DOCUMENT>0001628280-20-005392.txt : 20200423
<SEC-HEADER>0001628280-20-005392.hdr.sgml : 20200423
<ACCEPTANCE-DATETIME>20200423164725
ACCESSION NUMBER:		0001628280-20-005392
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200421
FILED AS OF DATE:		20200423
DATE AS OF CHANGE:		20200423

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Morris Dennis Patrick
		CENTRAL INDEX KEY:			0001809192

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13490
		FILM NUMBER:		20811609

	MAIL ADDRESS:	
		STREET 1:		7026 TEAL LOOP
		CITY:			GIG HARBOR
		STATE:			WA
		ZIP:			98335

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MITCHAM INDUSTRIES INC
		CENTRAL INDEX KEY:			0000926423
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-EQUIPMENT RENTAL & LEASING, NEC [7359]
		IRS NUMBER:				760210849
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			0131

	BUSINESS ADDRESS:	
		STREET 1:		8141 SH 75 SOUTH
		STREET 2:		PO BOX 1175
		CITY:			HUNTSVILLE
		STATE:			TX
		ZIP:			77342
		BUSINESS PHONE:		9362912277

	MAIL ADDRESS:	
		STREET 1:		P O BOX 1175
		CITY:			HUNTSVILLE
		STATE:			TX
		ZIP:			77342
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_158767482709655.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-04-21</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000926423</issuerCik>
        <issuerName>MITCHAM INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>MIND</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001809192</rptOwnerCik>
            <rptOwnerName>Morris Dennis Patrick</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7026 TEAL LOOP</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GIG HARBOR</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98335</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Operating Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>MII Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Option to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2030-03-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>MII Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>250000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock vest 1/3 on March 31, 2021, 1/3 on March 31, 2022 and 1/3 on March 31, 2023.</footnote>
        <footnote id="F2">Options vest 1/3 on March 31, 2021, 1/3 on March 31, 2022 and 1/3 on March 31, 2023.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert P. Capps, Attorney-in-Fact for Dennis P. Morris</signatureName>
        <signatureDate>2020-04-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
