PROJECT: YanChang Oilfield Limited Liability Company Shallow Horizontal Well Integrated Drilling Services 

DATE: Jun,2014

LOCATION: Yanchang County, Yanan City, Shaanxi Province

Background

In Yanchang oilfield, development is limited by reservoir of low permeability and ultra-low permeability. Low daily production, high development cost, fast production decrease have became the features of the development in Yanchang oilfield. It is difficult to keep output.

Solution

In Yanchang oilfield, improving production efficient according to horizontal well drilling and completion technology is the key technological means to solve the problems, which are more wells, low production rate, low output. But, drilling and completion engineering of shallow extended reach well has many difficulties, such as, it is difficult to RIH casing to bottom because of light self-weight and big dogleg; it is difficult to adjust trajectory in horizontal section in the reason of drilling strings’ self-weight can not overcome the friction drag; pay zone’s TVD is small and trajectory control precision is high, then it is difficult to performe trajectory control.

Based on the analysis of the difficulties above, technical service team optimized wellpath planning, performed friction reduction technology research and completion string RIH technology research.

Achievement

· Qiping1 well is the first ultra-shallow extended reach horizontal well in Yanchang oilfield. The successful performance of Qiping 1 well got a large technical breakthrough for the development of Yanchang oilfield. Technical indexes are as follow:

· TD is 1366m, TVD is 488.45m, horizontal section length is 750m, displacement is 1003.58m, horizontal displacement to vertical depth ratio is bigger than 2.

· Daily production is 10 times of adjacent wells.

Qiping1 Hookload comparison diagram

Qiping1 Friction comparison diagram