At least two dozen lawmakers own investments in the three companies tied to the Gulf of Mexico oil spill as Congress investigates the disaster and considers reforms. Lawmakers own amounts ranging from $1,000 to $150,000 worth of BP PLC, Transocean Ltd. or Halliburton Co. stocks and bonds, according to their personal financial disclosures. Several of these lawmakers sit on a committee examining the spill and what changes might be needed to prevent another.