The present disclosure is directed to the production of oil, gas, or other resources from subterranean zones.
Subterranean zones from which oil, gas, or other fluids are produced can include multiple production zones, which may comprise different sedimentary layers, different rock formations, zones of different pressure regimes, or other divisions such that concurrent production of the fluids from multiple different productions zones is desired but for reasons of safety, pressure management, flow control, or other reasons it is desired to not commingle the fluids produced from, and to independently control fluid flow from, the individual production zones.
Certain aspects of the subject matter herein can be implemented as a method for producing fluids from a wellbore drilled into a subterranean zone from a surface of the Earth. The subterranean zone includes at least an upper production zone and a lower production zone, and the method includes disposing in the wellbore a tubular production string that includes an upper string portion and a lower string portion, an inner diameter of a central bore of the upper string portion greater than an inner diameter of a central bore of the lower string portion. Joining a downhole end of the upper string portion with an uphole end of the lower string portion is a crossover assembly including a seal receptacle configured to receive a downhole end of a tubular insert having an outside diameter less than the inner diameter of the central bore of the upper string portion. The production string also includes an upper interval control valve (ICV) positioned on the production string and a lower ICV positioned on the production string downhole of the upper ICV. The method further includes positioning the production string within the wellbore such that the upper ICV is proximate an upper production zone perforation and the lower ICV is proximate a lower production zone perforation. After disposing the production string in the wellbore, a tubular insert is disposed within the central bore of the upper string portion and a downhole end of the tubular insert is inserted into the seal receptacle of the crossover assembly, thereby forming an interior annular volume defined at least in part by an inner surface of the central bore of the upper string portion, an outer surface of the tubular insert, and the seal receptacle. After inserting downhole end of the tubular insert into the seal receptacle, the upper ICV and the lower ICV are opened, thereby permitting a flow of fluids from the upper production zone through the upper ICV to the surface through the interior annular volume and also simultaneously permitting a flow of fluids from the lower production zone through the lower ICV to the surface through a central bore of the tubular insert via the central bore of the lower string portion without commingling with fluids flowing through the upper ICV.
An aspect combinable with any of the other aspects can include the following features. An inner diameter of the tubular insert can be substantially the same as the inner diameter of the central bore of the lower string portion.
An aspect combinable with any of the other aspects can include the following features. The downhole end of the tubular insert can be uphole of the uphole end of the lower string portion when the downhole end of the tubular insert is inserted into the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The crossover assembly can include a tapered surface configured to guide the downhole end of the tubular insert into the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The downhole end of the tubular insert can be releasably connected to the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The tubular insert can further include a sliding sleeve, and the method further includes, after the tubular insert is inserted in the seal receptacle, opening the sliding sleeve to permit flow of a lifting gas from the central bore of the tubular insert into the interior annular volume.
An aspect combinable with any of the other aspects can include the following features. The lifting gas can be pumped from a coiled tubing string disposed in the central bore of the tubular insert.
An aspect combinable with any of the other aspects can include the following features. Opening the upper ICV can be in response to a hydraulic signal conveyed to the upper ICV via a hydraulic control line extending downhole from a wellhead assembly.
An aspect combinable with any of the other aspects can include the following features. The hydraulic control line can be a first hydraulic control line and opening the lower ICV can be in response to a hydraulic signal conveyed to the lower ICV from a second hydraulic control line extending downhole from the wellhead assembly.
An aspect combinable with any of the other aspects can include the following features. The flow of fluids from the upper production zone through the upper ICV can be simultaneous with the flow of fluids from the lower production zone through the lower ICV.
An aspect combinable with any of the other aspects can include the following features. The production string can further include a production packer disposed around an exterior portion of the production string between the upper ICV and the lower ICV. Before inserting the downhole end of the tubular insert into the seal receptacle of the crossover assembly, the production packer can be set thereby isolating an annular volume exterior of the production string uphole of the production packer in fluid communication with the upper production zone perforation from an annular volume exterior of the production string downhole of the production packer in fluid communication with the lower production zone perforation.
Certain aspects of the subject matter herein can be implemented as a system for producing fluids from a wellbore drilled into a subterranean zone from a surface of the Earth that includes at least an upper production zone and a lower production zone. The system includes a tubular production string disposed in the wellbore, the tubular string including an upper string portion and a lower string portion, an inner diameter of a central bore of the upper string portion greater than an inner diameter of a central bore of the lower string portion. The production string further includes a crossover assembly joining a downhole end of the upper string portion with an uphole end of the lower string portion, the crossover assembly including a seal receptacle configured to receive a downhole end of a tubular insert having an outside diameter less than the inner diameter of the central bore of the upper string portion. The production string also includes upper interval control valve (ICV) positioned on the production string proximate an upper production zone perforation and a lower ICV positioned on the production string downhole of the upper ICV proximate a lower production zone perforation. The system further includes a tubular insert disposed within the central bore of the upper string portion, a downhole end of which is inserted into the seal receptacle of the crossover assembly, thereby forming an interior annular volume defined at least in part by an inner surface of the central bore of the upper string portion, an outer surface of the tubular insert, and the seal receptacle. The system is configured such that opening the upper ICV and the lower ICV permits a flow of fluids from the upper production zone through the upper ICV to the surface through the interior annular volume opening the lower ICV and, simultaneously, a flow of fluids from the lower production zone through the lower ICV to the surface through a central bore of the tubular insert via the central bore of the lower string portion without commingling with fluids flowing through the upper ICV.
An aspect combinable with any of the other aspects can include the following features. An inner diameter of the tubular insert can be substantially the same as the inner diameter of the central bore of the lower string portion.
An aspect combinable with any of the other aspects can include the following features. The downhole end of the tubular insert can be uphole of the uphole end of the lower string portion when the downhole end of the tubular insert is inserted into the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The crossover assembly can include a tapered surface configured to guide the downhole end of the tubular insert into the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The downhole end of the tubular insert can be releasably connected to the seal receptacle.
An aspect combinable with any of the other aspects can include the following features. The tubular insert further can include a sliding sleeve configured such that opening the sliding sleeve permits flow of a lifting gas from the central bore of the tubular insert into the interior annular volume.
An aspect combinable with any of the other aspects can include the following features. The lifting gas can be pumped from a coiled tubing string disposed in the central bore of the tubular insert.
An aspect combinable with any of the other aspects can include the following features. The system can also include a hydraulic control line configured to convey a hydraulic control signal to the upper ICV.
An aspect combinable with any of the other aspects can include the following features. The system can also include a hydraulic control line configured to convey a hydraulic control signal to the lower ICV.
An aspect combinable with any of the other aspects can include the following features. The flow of fluids from the upper production zone through the upper ICV can be simultaneous with the flow of fluids from the lower production zone through the lower ICV.
An aspect combinable with any of the other aspects can include the following features. The system can further include a production packer disposed around an exterior portion of the production string between the upper ICV and the lower ICV, the production packer isolating an annular volume exterior of the production string uphole of the production packer in fluid communication with the upper production zone perforation from an annular volume exterior of the production string downhole of the production packer in fluid communication with the lower production zone perforation. The tubular insert can disposed within the central bore of the upper string portion after the production packer is set.
In accordance with some embodiments of the present disclosure, a method and system which can enable an operator to produce fluids from one or more production zones without commingling them with fluids produced from other production zones, while selectively controlling flow of fluids from each zone. The method and system is simple, inexpensive, and efficient, and the system can be easily and efficiently constructed and removed (in whole or in part). The system also isolates the casing from any formation fluid by containing the two flow paths inside the inner tubing and the tubing-tubing annulus. This can protect the production casing from any corrosion or erosion induced by the flow in the casing-tubing annulus.
Referring first to
In the illustrated embodiment, casing string 214 (which can be comprised of multiple tubular casing segments of varying diameters) has been installed and cemented in place within wellbore 202 to stabilize the wellbore in accordance with conventional methods.
To provide a pathway for oil, gas, or other materials to be produced from upper production zone 210 to enter wellbore 202, upper zone perforations 216 have been formed through casing 214 and into upper production zone 210. Likewise, to provide a pathway for oil, gas, or other materials to be produced from lower production zone 212 to enter wellbore 202, lower zone perforations 218 have been formed through casing 214 and into lower production zone 212. Perforations 216 and 218 can be formed, for example, via shaped explosive charges or other means.
Referring now to
Production string 220 includes a crossover assembly 273 which joins the downhole end of the upper string portion 224 with an uphole end of the lower string portion 226. As described in more detail in reference to
Production string 220 further includes an upper interval control valve (ICV) 250 positioned on production string 220 and a lower interval ICV 252 positioned on production string 220 positioned on production string 220 downhole of upper ICV 250. In some embodiments upper ICV 250 is a 7-inch ICV and lower ICV 252 is a 3½-inch ICV. A first hydraulic control line 260 is configured to transmit hydraulic signals (for example, an initiation, cessation, a change in hydraulic pressure, or a pressure cycling) to upper ICV 250 and second hydraulic control line 262 is configured to transmit hydraulic signals to lower ICV 252.
Production string 220 in the illustrated embodiment further includes two production packers: a first production packer 230 disposed around an exterior portion of production string 220 between upper ICV 250 and lower ICV 252 and a second production packer 232 disposed around an exterior portion of production string 220 uphole of upper ICV 250. Packers 230 and 232 can include feedthroughs through which control lines 260 and 262 can pass without compromising the pressure seal of the packers.
Production string 220 in the illustrated embodiment includes pressure and temperature gauges 270 and 272 to monitor the pressure and temperature of fluids flowing through ICVs 250 and 252, respectively. The pressure and temperature data can be used by an operator to analyze reservoir performance and to monitor control of production settings for the ICVs.
Production string 220 in the illustrated embodiment further includes a sliding sleeve 240 which can selectively provide fluid communication between central bore 225 and the tubing-casing annulus exterior of production string 220, uphole of packer 232.
Proceeding to step 104 of
Proceeding to step 106 of
Proceeding to step 108 of
Proceeding to step 110 of
Proceeding to step 112 of
After completion of the lifting gas injection of step 116, or if at step 114 the production test is positive (i.e., adequate flow from lower production zone 212 is observed), the method proceeds to step 118 in which lower ICV 252 is returned to a closed position.
Proceeding to step 120 of
Proceeding then to step 132, and as shown in
In this disclosure, “approximately” or “substantially” means a deviation or allowance of up to 10 percent (%) and any variation from a mentioned value is within the tolerance limits of any machinery used to manufacture the part. Likewise, “about” can also allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range.
The term “uphole” as used herein means in the direction along a wellbore from its distal end towards the surface, and “downhole” as used herein means the direction along a wellbore from the surface towards its distal end. A downhole location means a location along a wellbore downhole of the surface.