The lessee shall exercise diligence in drilling and operating wells for oil and gas on the leased lands while such products can be secured in paying quantities; carry on all operations in a good and workmanlike manner in accordance with approved methods and practice, having due regard for the prevention of waste of oil or gas developed on the land, or the entrance of water through wells drilled by the lessee to the productive sands or oil or gas-bearing strata to the destruction or injury of the oil or gas deposits, the preservation and conservation of the property for future productive operations, and to the health and safety of workmen and employees; plug securely all wells before abandoning the same and to shut off effectually all water from the oil or gas-bearing strata; not drill any well within 200 feet of any house or barn on the premises without the lessor's written consent approved by the Area Director; carry out at his expense all reasonable orders and requirements of the supervisor relative to prevention of waste, and preservation of the property and the health and safety of workmen; bury all pipelines crossing tillable lands below plow depth unless other arrangements therefor are made with the Area Director; pay the lessor all damages to crops, buildings, and other improvements of the lessor occasioned by the lessee's operations: Provided, That the lessee shall not be held responsible for delays or casualties occasioned by causes beyond his control.