Intersected Well Drilling and Its Application to Brine Exploration and Production

Abstract:

wo wells some hundreds meters apart to be intersected in the depths underground are subject to identical space coordinate at the intersecting point. Much importance was attached to wellbore-intersecting design, trajectory controlling, the drilling of horizontal Interval, wellbore stability and data processing. To this end, a practical prediction of wellborn trajectory was modelled, optimied drilling with downhole prediction was adopted, diamond bit and drilling tools for building angle were researched and developed. Six pairs of brine wells have been intersected successfully by controlled directional drilling using downhole mud motor. Among them,one pair of mid- radius horizontal wells was intersected, another pair comprising a mid-radius horizontal well and a straight well was intersected. Principal specifications are shown as table 1.Using the wellbore-intersecting technology, traditional single-wells were turned into a through twin-well to extract aqui-soluble brine, from which the output is over three times more than the sum of that from two of single-well; ore recovery had seen a doubling; brine concentration registered a 15 % -20% rise; innal costs of mine construction can be cut by 47 %;the through well can last 20-year with less downhole failure. This technology can be used for production drilling of uranium and soluble deposits, deeply hidden deposit exploration, and coal-bed gas exploitation