Repeal of the Social Security minimum benefit for future retirees may harm fewer people than feared, according to a study by the Social Security Administration.

The study, published in the Social Security Bulletin, indicates that about four-fifths of those who will lose eligibility for the minimum as a result of repeal are housewives, but that a high proportion of them actually will lose nothing and in fact may obtain a higher benefit by applying for the wife's free benefit and forgoing benefits based on her earnings.

Under the minimum-benefit provisions, any person retiring on his or her own earnings record is guaranteed a a basic benefit of at least $122 a month.

Congress, at the request of President Reagan, repealed the minimum guarantee last year for 3 million people already receiving it as well as for all people coming on the Social Security rolls in the future. In the face of angry protests, however, Congress eventually restored the minimum for those already on the rolls.

Still, anyone coming on the rolls after Jan. 1, 1982, was to lose the guarantee.

The study looked at 165 people who first became eligible for benefits in November and who had such low earnings over their lifetimes that the benefits computed from their earnings records would have been lower than the minimum.

The study found that 129 of the 165 were housewives. However, 83 out of the 165 were eligible for a wife's benefit, which is available to any married woman 62 or older whose husband is drawing benefits, provided she gives up any benefit based on her own earnings record. The wife's benefit is equal to 50 percent of her husband's.

Some of the remaining 82 persons in the study were expected to become eligible for spouse's benefits later, although the study could not determine the exact number.

Seventeen others were federal, state or local government employes whose records indicated long enough government employment for probable entitlement to pensions from their employers.