Research On Posture Detection Technology Of Parallel-Horizontal Drilling Wells In Steam-Assisted Gravity Drainage Craft

With the increasing demand of oil and decreasing oil reserves, the exploitation of heavy crude oil reservoir becomes much more important. Seeing that conventional vertical well methods can't get a good result, it's very significant to study the measurement-control technology of parallel-horizontal wells in steam-assisted gravity drainage (SAGD) which is a very effective method in developing heavy crude oil reservoirs, especially extra heavy oil reservoirs.In this context, this dissertation studies the detection of drilling tool's attitude and related positioning and orientation technology, which is to detect the drilling tool's three-dimensional attitude in the actual drilling, and then solve all this information in a three-dimensional way, therefore controlling the next drilling direction.To achieve the purpose above, Firstly, the dissertation makes a fixed-point measurement method, to find the appropriate position between drilling tool and rotary magnet, and then proposes a new approach of determining based on triaxial fluxgate principle, and makes joint measurement by triaxial fluxgate sensor and accelerometer, determining the three attitude angles of drilling tool. Finally, in order to compensate for the effects of perturbing magnetic fields associated with magnetic materials in the surrounding environment, a correction method which relies on the knowledge of local geomagnetic field and interference magnetic field is described in great detail.In the process of drilling the SAGD wells, it finds the appropriate position between drilling tool and rotary magnet by fixed-point measurement, inducts varied magnetic field generated by rotating magnet in the environment by using triaxial fluxgate sensor and makes joint measurement with accelerometers, to determine vertical distance between the parallel-horizontal wells and drilling tool's attitude, which is tilt angle, tool face angle and azimuth, then it utilizes correction methods to eliminate errors associated with magnetic materials in the surrounding environment, to determine the next drilling direction and keep the trajectory of the upper and lower horizontal well parallel. At last, through the whole system's integrated adjustment, it achieves the basic design objectives. This article also finds inadequate for experiments that require further improvement, gives some advices to improve the performance of the instruments.